The LWCG Crossover Tether Keeper keeps your tether locked in to the top belt of the Crossover, thus advancing your tether every time you move the top platform. The tether keeper is made from TPU offering extreme durability and flexibility to accomodate tethers 8mm - 9.5mm. It is recommended to purchase 5-6 of these to keep your tether neat and organized on the top belt.