Spread their lips and keep their mouth open. This locking gag features a 1.5 in. diameter opening at the front, the perfect size for accepting all sorts of objects. A rolling buckle at the back locks in place easily with the addition of a standard small size lock (not included) and is adjustable to fit most any size head. The tunnel gag extends slightly into the mouth, which keeps the teeth and tongue out of the way. The gag is made of sturdy steel and genuine leather. Fits heads between 19 and 26 in. circumference, 4 in. width.