Applied to the glass deburring sharpening surface dimension:3/4''*4'' diamond grid:double side(400#600#) package:blister and card features:super strong plastic handle,comfort design How to use 1.according to the situation of cutting tool choice knife surface,hold knvies 2.keep the sharpener along the blade,blade angle is moderate,with proper strength to pull back and forth still can,generally 3 to 5 times