This is a rectangular, hard-chrome 100mm x 25mm file and was specifically made for sharpening skis & boards. Preferred exclusively by many professional technicians. Can also be used for base filing and fit our Base Bevel Guides. Cut 10 (10 teeth/cm) is best for new skis, hardened edges or removing edge quickly. Cut 14 (14 teeth/cm) is recommended for everyday use and Cut 16 (16 teeth/cm) is best for finishing and speed skis before Diamond or Ceramic Stones are used. Note: Longer files are not recommended to tune side-edges since they don't work well on the sidecut and may affect the accuracy of the bevel.