The Muscle cocksheath is Oxballs new and improved version of the Gym Boy. Muscle - smooth on the outside so it will slip in nice and easy, ribbed on the inside so you get in on the fun as well. Cocksling design at the base anchors this mammoth extender to your own cock and ensures it stays put - no matter hard hard you play.includes a TPR "Tip Stuffer" that helps maintain firmness of the extender if your own cock doesn't reach all the way in. Just grip the shaft and squeeze out the air, this creates vacuum that'll suck MUSCLE down onto you. Made of Max-Flex TPR a skin safe, phthalate-free rubber that is non-toxic and approved for use in sex-toys and stretches to 6x it's size.