Bit gag
From wipipedia.org
A bit gag is based on a horse bit and is often used in pony play. As a tool for silencing a sub it is much less effective than a ball gag, however the visual impact is as great (some might say greater) than a ball gag. The risks of wearing a bit gag are much less than a ball gag since it does not obstruct the airway.
Bit gags are also valuable tools for humiliation exercises, since they tend to cause the wearer to drool freely.
