It's a strapless strap-on designed to give skin-on-skin contact without breaking the continuity of action to adjust straps and buckles. It works!?A person uses their internal muscles to hold it in place with the bulb as the shaft protrudes at a natural angle. The Tantus Strapless*?Slim is easier to hold and control than the original; the Slim is 10% lighter than the original model. making it lighter for the driver. Vibrator: Single Speed Removable Waterproof Bullet Vibe. Uses 3 x LR44 Type Batteries. Dildo Diameter: 1.25 . Dildo Length: 5.5. Bulb Diameter: 1.5. Bulb Length: 2.5.