Play your way. This Vac-U-Lock attachment in smooth silicone features an abstract phallic design with a stimulating molded head and can be used with any Vac-U-Lock compatible harness or accessory. The Smooth Silicone Attachment is also o-ring harness compatible. Vac-U-Lock is the worldb s first and only patented pleasure system, revolutionizing harness play and offering endless possibilities to mix and match within your collection to build the perfect toy.