The first major breakthrough in wear bar technology since the 1950s. Unique corner-carving hourglass design yields better control at speed with no increased steering effort. Better tracking on trails - hourglass wear bar shape catches snow from ski sides to make steering more positive. Average of 1' - 2' tighter turning radius in soft snow conditions. 20% lighter than conventional 1/2" diameter round wear bars. Zinc-plated for corrosion resistance. Lifetime wear rate is nearly equal to current round and square wear bar types. Manufactured by Stud Boy. Designed and tested by USI. Some models require drilling extra holes in the skis..