Play your way. This Vac-U-Lock attachment in smooth silicone boasts an abstract phallic design with a stimulating molded head, making it compatible with any Vac-U-Lock harness or accessory. The Smooth Silicone Attachment is also o-ring harness compatible. Vac-U-Lock is the world's first and only patented pleasure system, revolutionizing harness play and providing endless possibilities to mix and match within your collection to create the perfect toy.