SM cock rings are sex toys used in BDSM play that can enhance sexual pleasure and prolong erections. These rings are typically made of materials like leather or metal. They are worn around the base of the penis, restricting blood flow and creating a more robust, longer-lasting erection. Cock rings can also be used as a form of erotic humiliation or to reinforce dominant-submissive dynamics in a BDSM relationship. As with any BDSM activity, it is essential to engage in cock ring use safely, with clear communication and consent from all parties involved.