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, by using your 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 wearer.