Vac-U-Lock Double Dong Plug Attachment by Doc Johnson

A double-ended strap-on attachment that plugs into any Vac-U-Lock harness, letting both partners feel mutual penetration and arousal simultaneously. One end slides inside the wearer while the other penetrates their partner, creating shared sensation and synchronised climax.

What it does

Unlike standard strap-on attachments where only one partner experiences physical sensation, this double-ended design creates a feedback loop of shared arousal. One end sits inside you while the other extends outward for your partner's penetration. As you thrust forward, the internal end pushes deeper into your most sensitive areas, building pressure that differs from external stimulation alone. Your partner's body creates delicious friction against the external end, intensifying sensation for you both.

Each forward motion drives the internal portion deeper while resistance from your partner generates waves of pleasure throughout your core. Your own movements become the source of your arousal, turning the act of penetrating your partner into direct physical feedback for yourself. Couples exploring strap-on play will find this attachment changes the dynamic from one-sided to mutual satisfaction. Browse Pornhub Sextoys for additional options in this category.

Specifications

• Total length: 5.7 inches
• Diameter: 1.10 inches throughout
• Design: Double-ended with internal and external ends
• Vac-U-Lock plug: Fits all compatible harness systems
• Material: Body-safe construction
• Surface: Smooth finish for comfortable insertion
• Construction: Firm design maintains shape during use

Fit and sizing

At 1.10 inches diameter, this attachment suits most comfort levels without overwhelming beginners, while the 5.7-inch length provides enough internal stimulation for experienced players. Sizing for strap-on attachments depends on your internal comfort and the depth that hits your most responsive spots consistently. Start by considering whether you prefer shallow or deeper internal pressure, then test positioning before vigorous play. Cockringshop specialises in products for men and couples, so check product reviews for how others with similar anatomy experience the fit. Size for sensation and comfort, never for ego—the right fit means you'll actually enjoy using it.

How to use it

Insert the Vac-U-Lock plug end into your harness until it clicks securely into place. Apply plenty of lubricant to the internal end, then position it against your opening. Slide the shorter end inside yourself first, adjusting your harness straps so the internal portion stays pressed against your most responsive areas. Angle the external end naturally toward your partner for smooth penetration.

Begin with gentle rocking motions to feel how the internal end responds to different angles and pressures. Watch for the angle that creates consistent pressure on your sweet spots—you'll notice when it hits right because your hips will want to buck forward involuntarily. Once positioned, each forward thrust drives the internal portion deeper while the external end penetrates your partner. After use, wash with warm soapy water and dry thoroughly before storage.

Feature breakdown

Who it suits

Couples exploring strap-on play will love how this attachment transforms the experience from one-sided pleasure to mutual satisfaction. It works best for wearers who enjoy internal penetration and want to feel physically connected to the penetration they're giving. If you find that the angle and depth hit your most responsive spots consistently, you'll discover this creates a unique sensation where your own thrusts generate pleasure waves throughout your core.

Skip this attachment if you prefer external-only stimulation or find internal pressure distracting when focusing on your partner. Some wearers find that internal sensation during penetration breaks their concentration or feels uncomfortable—that's valid, and a traditional single-ended attachment may suit you better instead. Honest self-assessment about whether internal sensation enhances or detracts from your experience matters more than any product feature.

How it compares

Standard strap-on attachments deliver sensation to one partner only—the wearer feels harness pressure and movement, but no direct internal feedback. Double-ended designs like this one create mutual physical sensation, so both bodies experience penetration directly. Rigid attachments like this maintain their shape completely, while some alternatives use flexible materials that bend and adjust. Browse Adam Eve Sextoys for other strap-on options and designs. Choosing between them comes down to whether you want mutual sensation (this design) or single-partner focus (traditional strap-ons).

What you can use it with

Pair this attachment with Anal Sex Toys if you're exploring double penetration during partnered play—one partner can use this attachment vaginally while another sex toy provides additional internal stimulation. The dual-sensation approach works well with complementary products that enhance mutual arousal. Plenty of lubricant becomes essential when layering multiple forms of stimulation, so factor that into your planning.

More from Doc Johnson

Doc Johnson makes quality American-made adult toys with body-safe materials and reliable construction. Explore the full Doc Johnson range for other strap-on attachments, harnesses, and couples' products designed with the same attention to detail and material safety.

Read more before you buy

Want to understand strap-on play better before committing? The Mind Blowing Strapless Strap On Evolution covers the evolution and variety of strap-on designs across the adult industry.

Why buy the Vac-U-Lock Double Dong Plug Attachment by Doc Johnson

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