Sharpen the most common drill bits in under a minute using an easy 3-step sharpening system that makes everyone a drill sharpening expert. The Darex V390 sharpens drill bits 1/8in.-3/4in. (3-19mm) and 118 to 140 with ease.Bit Sizes : 1/8 to 3/4 SAE.Bit Sizes : 3 to 19 mm.Angle Sharpening : 118 to 140 deg.Cobalt Bits: Yes .Includes an adjustable split-point feature and relief control for greater point style variation.Recommended for light duty 35-50 drills per week.Comes standard with Borazon wheel for HSS and cobalt drill bits.Optional diamond wheels for carbide bits sold separately.