How to Use a Strap-On Harness with a Vac-U-Lock Plug
By Doc Johnson | Official Store for Adult Toys, Enhancers & Lubes | Published: 2026-10-29
Category: How-to Guides
Learn how to attach and use a Vac-U-Lock strap-on harness with a plug, including setup steps, fit tips, and common mistakes to avoid.
Quick Answer
To use a strap-on harness with a Vac-U-Lock plug, attach the dildo's Vac-U-Lock base to the harness's plug, then adjust the waist and leg straps for a secure, comfortable fit before play.
Why the Vac-U-Lock Plug Matters
The Vac-U-Lock system uses a patented plug-and-socket design that locks a compatible dildo firmly in place. This means no slipping or wobbling during use, which makes it a popular choice for beginners and experienced users alike.
The plug opening is positioned to allow for natural anatomy, so both men and women can wear the harness comfortably. For men, the opening is high enough to let the penis hang below, which adds to the versatility of the system.
Adjustability and Fit
A good fit is key to comfort and control. The Ultra Harness features an adjustable waist up to 53 inches, making it suitable for a wide range of body sizes. The open crotch design provides easy access and helps prevent chafing during extended wear.
When adjusting, make sure the harness is snug but not too tight. You should be able to slide two fingers between the strap and your skin. This ensures the harness stays in place without restricting blood flow or causing discomfort.
Step-by-Step Setup and Use
- Attach the dildo to the harness: Insert the Vac-U-Lock base of your dildo into the plug on the harness until it clicks or fits snugly. Make sure it is fully seated to prevent it from coming loose during use. Test the connection by gently pulling on the dildo before wearing the harness.
- Put on the harness and adjust the waist: Step into the harness and pull it up to your waist. Tighten the waist strap so it is snug but comfortable, and ensure the plug is positioned correctly for your anatomy. Check that you can slide two fingers under the waist strap—if it's too tight, loosen it slightly.
- Adjust the leg straps (if applicable): If your harness has leg straps, adjust them so they sit comfortably around your thighs without digging in. This helps keep the harness stable during movement. Make sure the straps are not twisted and that they allow for full range of motion.
- Test the fit and security: Move around, bend, and squat to ensure the harness stays in place and the dildo doesn't shift. If anything feels loose, tighten the straps or re-seat the dildo. A secure fit means you can focus on play without worrying about adjustments.
- Clean and store after use: After use, remove the dildo and clean both the harness and the dildo according to the manufacturer's instructions. Store them separately to maintain their condition. Proper cleaning and storage extend the life of your products and keep them hygienic.
Recommended Products
- Vac-U-Lock - Ultra Harness - With Plug: The Ultra Harness with a Plug has an adjustable waist up to 53 inches, an open crotch for maximum comfort, and is designed for use by women or men. This harness offers a secure, adjustable fit for a wide range of body types, and the open crotch design makes it easy to wear for extended play.
Vac-U-Lock - Ultra Harness - With Plug - Body Extensions - BE Daring 2-Piece Set - Silicone Harness with 7" Bulbed Dong: The Body Extensions BE Daring 2-Piece Set includes an elastic and premium silicone harness plus a 7-inch bulbed dong, designed for maximum comfort and durability. This all-in-one set is a great option for beginners who want a complete strap-on system without having to buy separate components.
Body Extensions - BE Daring 2-Piece Set - Silicone Harness with 7" Bulbed Dong
