Made from smooth but stiff leather, this posture collar is uniquely tailored to firmly hold the head up, providing support where needed. In the front there is a heavy-duty O-ring for leash or rope bondage. It secures in the back with polished metal buckle. The small posture collar fits necks from 11" - 15". The medium size fits necks 13" to 17" and the large size fits necks 15" to 19". The different width of the collars also get wider as the size get bigger.