This high quality medical device is used by dentists and doctors to keep the mouths of their patients open during procedures. The hinge has a ratcheting feature that securely holds the gag open once you set it into place. Just press the lever to easily close the gag. A twist on our classic Jennings Gag, our newest version has a black rubber coating, for comfort as well as to keep the gag from slipping. We have added a secure neck strap, to help keep it in place. Measurements: Adjustable from 18 to 24 inches in circumference. Opens to 2 inches in width. Material: Stainless steel, PVC, PU leather.