Tent cords lose elasticity over time, so, to have a shelter ready to withstand almost anything out there, replace the slack ones in your kit with this silicone-based set. Made out of high-quality materials, these shock cords last longer than standard rubber and stay strong and firm in temperatures down to -40? F.. . ?. . . Length: 30 ft.. With a strong silicone core. Lasts longer than rubber. Stays firm down to -40? F. Comes with instructions for replacing tent pole shock cords. Imported.