Allows sled skis to glide with ease. Specifically designed traction knobs provide improved traction for your feet. Oval mounting channels and custom shoulder screws prevent warping by allowing for expansion and contraction that results from varying temperature. Exclusive venting, protects the deck of your trailer from moisture damage. Each box contains 8 pieces 13.5" x 29.5" (34.3 cm x 74.9 cm). Comes with 72 specially coated screws with grommets. Total length of 20' (6 m).