Oxballs Screwballs are the real alternative to cheap jelly cock rings. When you're getting down to it, the last thing you want is for your cock ring to roll up and grab you by the short and curlies! If you're new to ball stretching, Screwballs makes a great beginner's ball stretcher! The Screwballs are made of thermoplastic rubber silicone, which means it's super stretchy - and can take on any size man with comfort and ease. They are safe to use with your favourite lube. This is the Black Screwballs.