4pc Deburring Cutter Set features four separate color coded cutters. Each color indicates the material that the cutter is intended for. Colored sleeves rotate to lock and unlock blades for easy changing. Unique rounded head blades offer safe deburring of drilled and machined holes, end milled areas, tubing, backside of holes and an almost unlimited amount of uses. Curved blades swivel freely to automatically follow shapes, contours and holes. Fowler, an American company, manufactures inspection and measurement instruments such as electronic indicators, calipers, bore gauges, and digital scales. The company, founded in 1946, is headquartered in Newton, MA.