These string suppression stoppers fit Hoyts with the round suppressors and Bowtech/Diamond Suppressors with round shape. These stoppers are super soft and long-lasting. They take that last little bit of noise out of the string suppressor on Hoyt bows. On the instructions for installation: don't remove the old stopper (even if it's warn and cracked, this simply fits over the old one, and you don't need glue to install it)