Uses the concave side design of Stud Boy's original Shaper Bars with a new dual-runner design One-piece design for light weight Turns like a performance runner Makes its own groove, so no darting on the trails Eliminates dual-runner drag so no top-end loss Self-cleaning design won't clog with snow, ice or rocks Won't snag on obstacles Extremely durable Available in 4.5", 6" and 9" of 60å¡ cutting carbide Sold each NOTE: Some models require drilling extra holes in skis. .