Excellent file for sharpening your carbide ferrules. The extra coarse and large size of 6.75"x 3" means speedy sharpening, and longer life with more surface area for filing. Extremely durable coarse diamond surface means the serious rollerskier can get a couple years of usage out of this. Use this for about 10 seconds on each ferrule before going out to ensure your tips stay sharp. You'll never go back to a small file after using this one.