The Dee ring has straight bars which provide a slight lateral guiding effect. It is fixed in the horse's mouth - its shape doesn't allow the bit to rotate. The Dr. Bristol mouth has strong action, resting on the bars of the mouth. It exerts its main pressure directly onto the tongue. The bit reacts to the riders hands - when they are raised the mouthpiece tilts forward so that the plate forms an acute angle to the sides of the mouthpiece. This exerts a strong pressure onto the tongue which is released when the riders hands are lowered. Korsteel bits are crafted from tough stainless steel. 5" standard bit.