Full cheek gag bit flexible rubber

Simple rubber: Sweetest bit, gives a lot comfort, ideal for sensitive horses.

Gag bit: Works on the horse's balance forces him to get his own balance. ant putting his weight on his hindquarters. It needs specific cheek parts. If can also be used with only one pair of reins, or with bit loops, or with 2 pairs of reins. 

Full cheek bit: The most channelising bit, often used for young horses.