Copper Players Mouth Piece with Keys Full Cheek Bit The Full cheek, has simple action on the lips. The main feature of the full cheek is to help steering by giving lateral control. This bit helps the young horse not used to aids or the adult horse presenting lack of flexibility. This bit has 6 1/2 cheeks and 11 mm mouth. All our Bits are High Quality German or Stainless Steel made by Coronet.