Bevel Bit with Copper Lozenge from Shires Equestrian. The Bevel rings gives a rein attachment below the mouth piece which creates a mild lever action. The Copper lozenge is kind and assists with salivation. Sizes: Measurement A = 16mm. B = 55mm sizes 4.5", 5". B = 70mm sizes 5.25", 5.5" & 6"