Collars may be used in role-playing games involving humiliation because they have connotations of control, especially when worn with a leash.
The most common material for a collar is leather,. Other materials include rubber, PVC, and metal, typically stainless steel. Many collars are constructed with several different materials, and may also be decorated in various ways. Collars often feature buckles, straps and hooks, padlocks and other attachments.