Andux Figure Skating Shoe Knife Skates Sharpener Hockey Knife Adjustable Sharpener BDMXQ-01 Standard: One side blade slot is 3.4mm (for hockey skates), the other side of the blade slot is 3.8mm (for figure skates), built-in millstone diameter is 12.2mm. Adjustable: If your blade thickness is beyond the standard blade slot, you can unscrew the screws on both sides of the sharpener to adjust it to the appropriate width then tighten the screws. Care for your ice skates. Shipping time: 9-12 working days.