sentences:  A basic bitting rig consists of a surcingle (also known as a roller) that has a number of rings on either side, placed at varying heights, usually with a crupper to prevent the surcingle from sliding forward.A bridle is also part of a bitting rig, with side reins and rings or small pulleys on either side of the browband to accommodate an overcheck.Some variations use pulleys and leverage on side reins to create a given "headset."