Maintain the EDGE is the only handheld hockey player skate sharpener on the market that automatically turns the sharpening stone to promote even wear for more consistent results. This is an essential feature for a long-lasting and effective sharpener. It’s what gives our products an extra EDGE. Our sharpener: Cuts the hollow just like a powered grinder Adjustable thumbscrews that keep the stone centered essential to match the blade you have and to even out the edges An industrial hard plastic handle that will not scratch or dull your blade A super abrasive diamond grit stone to cut the hollow giving the longest life available. Convenient deburring stone attached to the back of the sharpener. It's the only sharpener that cuts the hollow and deburs the edges all in one convenient tool. The Pro version has an upgraded Diamond stone for a much longer life. Please note: Our sharpeners are designed for hockey player skates only, and are not intended for use on goalie skates or figure skates.