Doc Johnson Vac-U-Lock Review: Dual-Density Strap-On Dildo Kit Tested

Whether you’re interested in pegging or simply looking for a more secure strap-on system, finding the right harness and attachment mechanism can make a significant difference. A poorly fitting setup may shift during use or fail to keep the toy securely in place, which can interrupt the experience. After trying a variety of strap-on systems over the years, Richard and I were curious to see how the Doc Johnson Vac-U-Lock system compared.

Rather than pairing a single dildo with a standard harness, the Doc Johnson Vac-U-Lock Strap-On Dildo Set offers a complete kit that includes a harness, multiple dildos, and the brand’s interchangeable Vac-U-Lock attachment system. The ability to swap between different sizes and styles without changing the entire setup adds a level of versatility that’s difficult to achieve with traditional strap-on kits. In this Doc Johnson Vac-U-Lock review, I’ll take a closer look at the build quality, comfort, ease of use, and overall performance to see whether this modular system lives up to its reputation.

Quick Verdict

The Doc Johnson Vac-U-Lock Dual Density Experienced Set is best for experienced strap-on users who want a complete kit with three realistic dildos, a padded harness, suction-cup option and secure Vac-U-Lock attachment system. Its biggest strengths are the 8-inch, 9-inch and 10-inch dildo options, dual-density Ultraskyn feel, 2-inch diameter, adjustable 69-inch harness, included accessories and strong attachment stability, while its main drawbacks are the porous TPE-based material, non-waterproof cleaning, advanced sizing and water-based-lube-only care.

• Best for: Experienced users and couples who want a versatile strap-on kit with multiple realistic attachments and secure harness play.
• Skip it if: You are a beginner, prefer non-porous silicone or want a fully waterproof toy that can be sterilized easily.
• Main strength: The Vac-U-Lock system keeps the dildo more stable than a basic O-ring setup, especially during active strap-on play.
• Main drawback: Ultraskyn is porous and cannot be fully sterilized, so condoms are strongly recommended for anal use or sharing.
• Final verdict: A feature-packed strap-on kit for experienced users who value size variety, realism and secure attachment over low-maintenance materials or beginner-friendly sizing.

What Is the Doc Johnson Vac-U-Lock Dual Density Experienced Set?

Before testing this complete kit, I had already spent time with another Doc Johnson toy that used the Vac-U-Lock system, and it left a very positive impression. Its secure locking mechanism and interchangeable design immediately stood out compared with traditional suction-cup or O-ring setups.

If you’re new to the Vac-U-Lock system, it’s designed to let you attach and swap compatible dildos quickly while maintaining a secure connection to the harness. That modular approach is one of its biggest advantages, making it easy to change toys without replacing the entire setup or interrupting the experience.

Vac-U-Lock is a special vacuum technology by Doc Johnson. It’s a super strong system for strap-ons as well as suction cups, and I honestly can’t believe I’ve lived without it all these years. What you’ll get with this kit are two different suction plugs. One of them acts as a suction cup base, which allows you to attach the included dildos to smooth surfaces like the floor, wall, or shower area for hands-free play. The other Vac-U-Lock suction plug in this kit fits inside the strap-on harness. It allows you to quickly attach your dildo to the harness, and then the vacuum system keeps it secure so you don’t have to worry about it slipping or falling off during use.

Now, dildos are by far one of Doc Johnson’s specialties. If you’ve read my earlier reviews, you know how much I enjoy this brand. What you’ll get in this strap-on dildo set are three different, generously sized dildos that you can use depending on your mood, comfort level, and type of play. Just open up the kit, choose your favorite attachment, secure it in place, and enjoy the extra variety this Vac-U-Lock strap-on set has to offer.

Three Included Dildos: Sizes, Shapes and Uses

Inside the package, you’ll find three realistic dildos ranging from approximately 8 to 10 inches in length, giving you a variety of sizes to suit different preferences and experience levels. The interchangeable design makes it easy to switch between them without changing the entire harness setup.

One of the things that impressed me most during my Doc Johnson Vac-U-Lock review was how comprehensive the kit is. Rather than purchasing the components separately, you get a complete system that includes the harness, multiple compatible dildos, and the Vac-U-Lock attachment mechanism, making it a versatile option for both partnered and solo use.

What’s Included in the Box?

Unboxing this kit is genuinely fun because there’s a lot included in the package. Instead of receiving just a harness and a single toy, you get a complete system with multiple accessories designed to help you get started straight away. I was pleasantly surprised by how comprehensive everything felt as I unpacked it.

The set includes three extra-large Ultraskyn dildos, a comfortable harness, interchangeable O-rings, and the Vac-U-Lock attachment components. It also comes with lubricant, toy cleaner, and refresher powder, making it a well-rounded package that requires very little additional setup before use. Overall, it’s one of the more complete strap-on kits I’ve tested.

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Doc Johnson Vac-U-Lock Features, Specs and Materials

• Strap-on kit for experienced users
• 3 Ultraskyn dual-density dildos: 10-inch Dong, 9-inch Slim with balls, 8-inch with balls
• All dildos share the same 2-inch diameter
• Soft padded adjustable harness (up to 69-inch waist)
• 3 O-rings
• Vac-U-Lock harness attachment plug
• Vac-U-Lock suction cup base
• Water-based lube sample
• Toy cleaner
• Ultraskyn refresh powder
• Material: Ultraskyn (TPE-based) – phthalate-free but POROUS – use with non-lubricated condoms for anal use
• Water-based lube only (silicone lube will degrade Ultraskyn)
• US and Canada warranty only (90 days to 1 year depending on product)
• Not waterproof – damp cloth clean only

Size, Insertable Length and Beginner Suitability

During my Doc Johnson Vac-U-Lock review, Richard and I tested all three dildos to see how each one felt in real use. The fun part was switching between the different sizes and shapes, then comparing which dildo felt the most comfortable, realistic, and satisfying for solo play, anal play, and strap-on use.

Honestly, all of these dildos are made using Doc Johnson’s Ultraskyn material, and the quality is pretty impressive. The biggest option in the set is the 10-inch Dong dildo. If that feels a little too large for anal play or beginner-friendly exploring, you can choose the 9-inch Slim Dildo with balls or the 8-inch Dildo with balls dildo instead. That variety is one of the best parts of this Vac-U-Lock strap-on kit because you can start smaller, build confidence, and switch attachments depending on your mood.

One of the standout features of all three dildos is their dual-density construction. Each model combines a soft, lifelike outer layer with a firmer inner core, creating a realistic balance of cushioning and structural support. This design helps the toys maintain their shape while still feeling comfortable during use.

I also appreciated that each dildo has its own distinct surface detailing. Although they all feature realistic sculpting, the textures and contours vary from one model to the next, giving the kit greater versatility and allowing you to choose the style that best matches your personal preferences.

For example, the 10-inch Dong has huge veins and a big bulbous head. The 8-inch dildo has a similar texture and head, although it’s smaller and has a big pair of balls attached to it. Then, the 9-inch Slim Dildo sits between those two. It gives you a thinner head along with a slightly tapered shaft. One thing to note here is that all of the dildos (even the thinner one) have the same width. While the 2-inch width is just perfect for me, they could have included different circumferences just to give you a bit more variety.

Ultraskyn Material, Porosity and Safety

Like Vac-U-Lock, Ultraskyn is another one of Doc Johnson’s inventions. It’s a TPE-based blend that’s compounded to feel like real skin. In short, the formula for these dildos is “top secret”. But, we know that TPE is the main ingredient.

Now, TPE is one of those materials that feels fantastic, especially when it’s used on dildos. However, it’s not the safest option out there. While TPE is phthalate-free and hypoallergenic, it’s highly porous. This means that it attracts and absorbs germs easily. That’s why it’s difficult to clean and store.

Frankly, I haven’t had any problems with Doc Johnson’s dildos so far, but you will need to know how to maintain them properly to keep things safe and hygienic. The upside is that you’ll get a flexible and resilient dildo that looks and feels impressively lifelike. It’s especially fun once you secure it in the harness and suddenly have a realistic strap-on ready for partner play. Still, you should use these dildos with non-lubricated condoms to help keep them cleaner and protect the material. If you don’t use condoms, the material may start to degrade and show signs of wear within a few months.

Harness Fit, Vac-U-Lock Attachment and Partnered Use

As mentioned earlier, the kit includes a complete harness, and I found it comfortable to wear thanks to its soft, padded construction. The additional padding helps distribute pressure evenly, making the harness feel secure during longer sessions without becoming uncomfortable.

The harness supports two different attachment methods. You can use the Vac-U-Lock suction adapter together with the included O-rings, or you can attach one of the supplied Vac-U-Lock plugs directly to a compatible dildo. During my testing, I found the second option to provide the most secure connection. It kept the toy firmly in place throughout use and made switching between the included dildos quick and straightforward, which is one of the biggest strengths of the Vac-U-Lock system.

In my experience, the 9-inch Slim Dildo and the 8-inch Dildo with Balls are best suited to users who already have some experience with anal play. Their larger dimensions make them a better fit for those who are comfortable with medium to large insertable toys.

If you or your partner are new to anal play, it’s best to begin gradually, use plenty of water-based lubricant, and choose the smallest, most manageable option before progressing to the larger models in the kit. Taking the time to warm up and communicate throughout the experience will help make the transition to larger toys much more comfortable.

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Suction Cup Base and Hands-Free Use

As I mentioned earlier in my Doc Johnson Vac-U-Lock review, this kit isn’t limited to strap-on use. By attaching one of the included dildos to the Vac-U-Lock suction system, you can secure it to a smooth, non-porous surface for stable hands-free use. It’s a simple feature that adds a great deal of versatility to the overall package.

Another advantage is that the remaining two dildos are ready to swap in whenever you want a different size or shape. Because the Vac-U-Lock system is designed for quick changes, it’s easy to switch between the included models without replacing the entire setup.

You can use the suction cup attachment for hands-free vaginal play and then get creative with the rest of the kit. I experimented with the 10-inch Dong, the 8-inch Dildo with balls, and the 9-inch Slim Dildo with balls to see how much variety this set could really offer. It was definitely a memorable testing session, and I can see myself coming back to this kit again for solo play and partnered fun. Between the three different dildos, the suction cup base, and the separate Vac-U-Lock harness base, this set is definitely a keeper. It feels like one of those versatile strap-on kits that can quickly become a favorite when you want options, stability, and plenty of room to play.

Doc Johnson Vac-U-Lock Compared With Other Strap-On Dildos

Show More

	Doc Johnson Vac-U-Lock	VixSkin Vixen Mustang	Hankey's Toys Ray Diesel	Uberrime The Grandis
features	Features a patented Vac-U-Lock system for secure attachment to compatible harnesses Crafted with lifelike detailing, including a textured shaft and pronounced head for enhanced stimulation and realism Made from high-quality, phthalate-free materials, ensuring safety and comfort during use Designed to fit most strap-on harnesses, offering versatility for various users Provides a balance of firmness for penetration with enough flexibility for comfort during use	Made from VixSkin’s signature dual density silicone, providing a soft, lifelike feel on the outside with a firm core for effective penetration Offers a flexible shaft that allows for comfortable positioning during use while maintaining structural integrity Simple to clean with warm water and mild soap or a dedicated sex toy cleaner, ensuring hygiene Suitable for both vaginal and anal play, catering to a variety of preferences Designed to work with most standard strap-on harnesses, providing versatility in use	Designed with a flared base for added safety, preventing the toy from slipping during use and allowing compatibility with harnesses Fully waterproof, making it suitable for use in the shower or bath and easy to clean Suitable for both vaginal and anal play, catering to a variety of preferences Designed for long-lasting use, maintaining its quality and performance even with regular play Crafted with a lifelike appearance and texture, featuring details like veins and a pronounced head	The flexible shaft allows for comfortable positioning and adapts to different angles during use Combines a soft outer layer for a realistic feel with a firmer inner core for effective penetration Features a distinctive, artistic design with a pronounced head and detailed texture Simple to clean with warm water and mild soap or a dedicated toy cleaner for hygiene Suitable for both vaginal and anal play, catering to a variety of preferences
price	From $45	From $155	From $205	From $210
users	232	195	27	18
our rating	4.8	4.5	3.8	3.5
power	Hand	Hand	Hand	Hand
material	Ultraskyn	Silicone	Silicone	Silicone
waterproof	Yes	Yes	Yes	Yes
brand	Doc Johnson	VixSkin	Hankey's Toys	Uberrime
type	Strap-on dildo	Suction cup dildo	Realistic strap-on dildo	Large dildo
allergens	Latex-Free, Phthalate-Free	Phthalate-free - Non-porous	Phthalate-free - Non-porous	Phthalate-free - Non-porous
design	4.7	4.7	3.9	3.4
ease of use	4.9	4.8	4	3.4
orgasm	4.5	4.6	3.7	3.9
quality	4.7	4.8	3.9	3.6
noise	Whisper Quiet	Whisper Quiet	Whisper Quiet	Whisper Quiet
ease of clean	Moderate	Easy	Easy	Easy
warranty	1 year	Lifetime	None	None

Doc Johnson Vac-U-Lock Review Verdict

The Doc Johnson Vac-U-Lock Dual Density Experienced Set genuinely delivers on its name. Three dual-density Ultraskyn dildos, a secure vacuum harness system, a suction cup base and a complete consumables package make this one of the most versatile strap-on kits available. The uniform 2-inch diameter across all three dildos is the biggest missed opportunity. The Ultraskyn porosity limitation requires condom use for anal play – this is non-negotiable and worth understanding before purchase. If you go in with clear expectations, this kit rewards with genuine versatility across solo and partner configurations.

Who Should Buy the Doc Johnson Vac-U-Lock Dual Density Experienced Set?

Mistakes to Avoid With the Doc Johnson Vac-U-Lock Set

1. Using Ultraskyn dildos for anal play without a condom. Ultraskyn is porous TPE – bacteria from anal use penetrate the material and cannot be removed by cleaning alone. This is not a preference, it is a hygiene and health requirement. Always use a non-lubricated condom for every anal session.
2. Using silicone or oil-based lube. Ultraskyn is TPE – silicone lubricants will chemically degrade the material surface. Water-based lube only, every time. This applies both directly to the dildo and to any condom you use with it.
3. Cross-contamination between anal and vaginal use. If a dildo has been used anally, even with a condom, treat it carefully before vaginal use. Change the condom, clean the dildo with toy cleaner and consider using a separate dildo for vaginal use in the same session.
4. Skipping the Ultraskyn Refresh Powder. Ultraskyn becomes tacky over time without the refresh powder, which also attracts lint and debris. Apply the included refresh powder after every clean and dry session. This significantly extends the material lifespan.
5. Mounting the suction cup on non-smooth surfaces. The Vac-U-Lock suction cup requires a smooth, non-porous surface to hold securely. Textured tiles, matte surfaces and wood will give inconsistent results. Test the hold before relying on it.

Doc Johnson Vac-U-Lock FAQ

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