The bungee martingale helps achieve a round outline through bit pressure when the horse raises his head too high. The rubber offers some elasticity to more gently encourage a softer outline and thereby improve muscle strength. The bungee martingale may be used when riding, or as a training aid when lunging if a training roller is used. This model features stainless steel clips to attach to the girth loop and bit rings. There is some adjustment in the straps that attach to the bit.