A ring cheek piece introduces poll pressure as well as creating leverage on the mouthpiece, the 2 1/2 Ring version is the softest out of the 3 or 4 ring alternatives as the 1/2 ring softens the leverage on the mouthpiece and poll. The Colin Miles is a great schooling bit with a wide centre piece creating greater tongue pressure and reducing bar pressure. The rings give the horse something to play with and help keep the horses attention on the bit. This particular joint exerts more pressure than the Control Plate or Elliptical.