Shires Mullen Mouth Pelham. This is a fairly light bit since the pressure is uniformly spread across the mouth. Suitable for horses with small or soft mouths. Can be used with twin reins or Pelham roundings. Mouthpiece thickness is 14mm. Cheek height is 115mm (4.5"), 130mm (5", 5.5"), and 140mm (6"). Stainless steel is the most prevalent material used in bits. Durable, easy to clean, tasteless, and will not rust.