Fine mouth stainless steel ring bit with "lozenge" shaped joint that sits flat on the tongue with rein pressure. Similar to "KK Training Bit" Sizes: Shetland/Small Pony Size - 4'' (10cm) Pony - 4.5'' (11.5cm) *Ring Size 45mm Cob - 5'' (12.5cm) Full - 5.5'' (14cm) *Ring Size 55mm