Ball Gag - A gag consisting of a ball held inside the mouth

Ring Gag - A gag which holds the mouth open with a ring

Cleave Gag - A gag, typically fabric or rope, which goes in the mouth and is pulled back

Cock Gag - A gag with a dildo attatched

Tape Gag - A peice or peices of tape covering the mouth

Plug Gag - A gag with a (typically removable) plug

Bit Gag - A horizontal bar, like a horse's bit

Harness Gag - A gag attatched to a facial harness

Cloth Gag - A peice of cloth which covers the mouth

Inflatable Gag - A gag which is able to be inflated, increasing it's size while in the mouth.