Stanley FatMax Xtreme Box Beam LevelDurable box beam construction is up to 5x stronger than other Stanley® levels. Block vials provide accuracy of 0.0005 in/in (0.5mm/m). Magnified center vial for improved visibility. Machined leveling surfaces improves accuracy. Accuracy: 0.0005 in/in; Body Material: Aluminum; Length: 48 in; Number of Vials: 3; Type: Builders Spirit Level; Vial Positions: 1 Level, 2 Plumb; Weight: 2.96 lb.