Trust Inno Sense Dee Flexi Soft BitWe absolutely love that the Trust Flexisoft D Ring bit gives the rider more leverage with making turns, the D shaped rings give more pressure on the horses' cheeks. The mouthpiece is made of Inno Sense Flexisoft, which makes the bit flexible. Therefore this mouthpiece is softer than sweet iron or copper. This D ring has a straight mouthpiece and gives mainly pressure on the tongue. D Ring bit Mouthpiece Circumference 20 mm Gives rider more leverage