Bon  88-305 Cast Stainless Steel 6-Inch by 4-/12-Inch Concrete Bullet Groover, 3/4-Inch Bit Depth by 3/8-Inch Bit Width with Comfort Grip Handle Made from cast stainless steel Comfort grip handle 6-Inch by 4-1/2-Inch US Patent No.7,610,648 The preferred choice of the professional tradesman