Inno Sense Port Medium 2.5 Ring BitInno Sense Port Medium 2. 5 Ring Bit bits with a flexible mouthpiece can be used for all horses but they're especially suitable for young horses and horses with sensitive mouths. The plastic is FDA approved, which means that the material is non toxic ad contains no plasticisers. In addition, the bits are very sturdy due to the use of a flexible core made of stainless steel. Available in 20 mm thickness Sizes: 12. 5 cm 13. 5 cm 14. 5 cm