The Schroth FHR twist anchor sliding tethers offer an alternative method of fixing an FHR device to a helmet. When used in conjunction with Schroth twist anchor FHR clips the tethers provide an easier method of attaching and detaching the FHR device from the helmet.FIA 8858-2010 approved for use in motorsportChoice of length for a more personalised fitEasier attachment and and detaching of FHR deviceThe twist anchor tethers are available in three different lengths. The recommended length is 18 which comes as standard on all new Medium and Large FHR devices. For users with open face helmets where the clips are located further back on the helmet or those looking for a slightly shorter version Schroth offers the 17 version. In addition a 19 version is available for use with XL FHR devices.Important - These tethers are suitable ONLY for attaching to Schroth twist anchor FHR clips which are available separately.