The advanced c-ring is a pure silicone cock ring with an internal diameter of 1.75” designed for use behind the balls. Put it on and it will provide good firmness enhancing tightness. The ring does have some stretch however not very much so you should measure yourself before buying. It has a 3/4 inch wide band that makes the toy comfortable as well as noticeably pushing the balls forward creating more ball-smacking as well as distending the testicles which will enhance orgasm and ejaculation.