This is a tool for checking the inside/outside balance of skate blades. It's handmade, so it has a few scratches, but it's new. After sharpening the blades, you might check the inside/outside balance with a coin or something, but it's not very accurate. I made this one myself. Why not give it a try? Please measure the blades after sharpening, not only for figure skating but also for ice hockey and other skates with grooves. As shown in the photo, place it in front and back and check if the front and back are parallel with the two gauges. You can easily check if the inside edge, especially with a strong edge, is worn down. Also, if you get your blades sharpened at a bad shop, the curve of the blade can be off. You can easily see this with this balance checking tool. Also, with leather boots, the soles are hard, so the blades can be bent. You can easily see this with this balance checking tool. This is a must-have item for athletes.