Heavy Duty Aluminum Frame and Bi-Material Body With Shock-Absorbing Rubber Ends. Lighted With Auto Shutoff. 3 Vials - (1) Level, (1) Plumb, (1) 45º. Accuracy of 0.002 in/in (2mm/m). Center Open Top Read Vial. Magnetic Strip For Hands Free Operation on Metal Surfaces. Pipe Groove for use on Rounded Surfaces. 2 Hang Holes.