Hello there, I need to know what is the name of this type or style of gag which is a harness style with a large open circular piece which forces open the mouth so objects can be inserted into the mouth. Some are covered with spikes or nubs. The harness has a strap that goes over the top of the head and divides to allow the nose to stick through it.

I know what its used for, but does it have a name and does any one have more pics of this gag in use? Thanks!