Darex PP11125GF Borazon Wheel for JVT390 Drill Bit Sharpener Borazon wheel Used for splitting the point on high-speed steel and cobalt drill bits Long-lasting, 180-grit wheel does not require dressing Sharpens approximate 2000 bits before needing replacement The wheel is standard on the V390 Borazon wheel Used for splitting the point on high-speed steel and cobalt drill bits when used with v390 tool-drill sharpener Long-lasting, 180-grit wheel does not require dressing Sharpens approximate 2000 bits before needing replacement The wheel is standard on the v390