True Blue Pro Heavy-Duty Magnetic LevelTrue Blue® vials are accurate to within 0.00050" per inch in all 10 level and plumb working positions. Super strong anodized I-beam frame. Strong holding magnetic edge. Shock absorbing end plates. Top read window. Body Material: Aluminum; Length: 48 in; Number of Vials: 3; Structure: I-Beam; Vial Material: Acrylic; Vial Positions: 2 Plumb, 1 Level; Weight: 2.90 lb.