Featuring a Maximum Spin Guarantee, the nU Groove Sharpener is a tool that should be in every golfer's bag! Over 10,000 sold. The nU Groove Sharpener is made from the highest quality metals in the USA. *Wedge Guys LLC can not speak to the quality and materials being used by other companies selling under our listing* nU Groove Sharpener - Golf Club Groove Sharpener, Re-Grooving Tool and Cleaner for Wedges & Irons - Generate Optimal Backspin by Restoring Your Old Irons - PGA Recommended - Made in USA 4" Length w/ Cross Hatch Grip