Vac-U-lock and Lock-on dildos and harnesses

When control is everything, your gear should hold as firmly as your authority. Vac-U-Lock and Lock-On dildos and harnesses click into place with a precision that never wavers, giving dominants the confidence to push limits and submissives the freedom to fully surrender. Mix and match shapes, sizes and textures across compatible systems to build a configuration that is entirely yours.

Whether you are commanding strap-on scenes, securing attachments to a bondage board or exploring pegging dynamics, these modular systems eliminate slippage so your focus stays where it belongs: on sensation, connection and the art of power exchange. Browse the full collection and lock in your next scene.

Buying guide

What is the difference between Vac-U-Lock and Lock-On systems?

Both are modular attachment systems that let you swap dildos and plugs in and out of a compatible harness or base, but they use different connector designs. Vac-U-Lock, developed by Doc Johnson, uses a hollow plug receptor in the toy that slots onto a corresponding peg on the harness or mount, creating a secure vacuum-assisted grip. Lock-On systems, popularised by brands such as Tantus, use a firm central post and locking ring that threads or snaps into the base of the toy. Neither system is universally interchangeable with the other, so check that your chosen dildo and harness share the same connector type before purchasing.

How do I choose the right harness for strap-on play or a bondage board?

Consider the following factors when selecting your harness or mount:

  • Intended use: Wearable harnesses suit body-to-body strap-on play, while bondage board or furniture mounts are built for restraint and positioning scenes.
  • Fit and adjustability: A harness should sit snugly against the body without digging in. Look for fully adjustable straps and a wide range of sizing.
  • Material: Leather offers durability and a classic aesthetic; nylon webbing is lightweight and easy to clean; neoprene adds padding and comfort for longer sessions.
  • O-ring vs modular connector: Standard O-ring harnesses accept many dildo bases, while Vac-U-Lock and Lock-On harnesses only work with their matching attachment system but provide far greater stability.

Are Vac-U-Lock and Lock-On dildos body-safe?

Body safety depends entirely on the specific toy, not the connector system itself. Look for dildos made from non-porous, body-safe materials such as silicone, borosilicate glass, stainless steel, or hard ABS plastic. Avoid jelly rubber, PVC, or TPE toys labelled as phthalate-free without third-party verification, as porosity makes thorough sterilisation impossible. Product listings on The BDSM Store include material information to help you make an informed choice. When in doubt, using a condom over the dildo adds an extra layer of hygiene.

How should I clean and care for modular dildo attachments?

Cleaning method depends on the material of the attachment, not the connector system:

  • Non-porous silicone, glass, and stainless steel: Can be boiled, run through a dishwasher on the top rack without detergent, or soaked in a 10 percent bleach solution and rinsed thoroughly. This allows full sterilisation between different users or types of play.
  • Hard ABS plastic: Wipe down with a toy cleaner or mild soap and warm water. Do not boil or submerge the connector plug area if it contains any internal components.
  • Harnesses: Leather harnesses should be wiped with a damp cloth and conditioned periodically. Nylon and neoprene harnesses can often be hand-washed or machine-washed on a gentle cycle. Always check the manufacturer guidance.

Allow all items to dry completely before storage to prevent bacterial growth or material degradation.

How do we negotiate and set boundaries before a scene involving strap-on or positional play?

Clear, enthusiastic consent and negotiation are foundational to any power exchange scene. Before play begins, discuss the following with your partner or partners:

  • Safe words and signals: Agree on a verbal safe word and, importantly, a non-verbal signal such as dropping an object or tapping out, in case speech becomes difficult during the scene.
  • Hard and soft limits: Establish what is off the table entirely and what can be explored with caution. Modular systems make it easy to switch attachment sizes, so agreeing on a size range in advance avoids pressure in the moment.
  • Physical considerations: Discuss any injuries, sensitivities, or anatomical considerations that affect positioning or depth.
  • Aftercare plan: Agree on what aftercare looks like for both the dominant and submissive partner. Aftercare may include physical comfort such as blankets and water, verbal reassurance, or quiet time together, and it is as important as any other part of the scene.