The Fowler 52-475-050-0 All-Angle V-block and clamp set with 1.312" holding capacity. The V-block has four 3/8”-16 tapped holes, two in the bottom and one on each side for angle non-clamping. The sides are parallel, and V is central and ground to .0003". The central hole is provided for drilling or removing pins. It is made with hardened and precision ground tool steel, which guarantees durability. All-Angle V-block and clamp set is perfect for grinding, milling or drilling. Fowler All-Angle V-block and clamp set comes with a full 1-year warranty on materials and workmanship. Fowler, an American company, manufactures premium inspection and measuring instruments like electronic indicators, calipers, bore gages, and micrometers. The company, founded in 1946, is headquartered in Canton, MA.