Cocksling super stretchy is the latest design by Oxballs. Cocksling is the best cock and ball piece that we have ever seen and used! The Cocksling design hugs every body part in just the right way. The Cocksling is made from heavy duty TPR (Thermoplastic Rubber). The Cocksling is very stretchy and can increase to more than double its size. Do not use oil based lubes.