These Edge Again Diamond Coated Figure Skate Tusk Replacements are specifically designed for the revolutionary Edge Again Figure Skate sharpener. They're extremely easy and safe to install with a slick snap-in, snap-out system. Each Edge Again Tusk will last sharpen approximately 30 pairs of skates. This figure skate tusk works on both the manual and powered Edge Again Figure Skate Sharpeners. Made specifically for figure skating!