Bombers Polo Big Ring Gag Elliptical RollerSize 135 The Elliptical Roller is stronger than the Control Plate due to it concentrating pressure onto a smaller surface area. This bit will suit a horse that pushes the bit with its tongue. The horse will draw its head back and tuck its chin in, finding a better balance of control. The roller keeps the horses attention on the bit. With bridle attachments.