Master Mechanic, 48", Aluminum Level, Has 3 Vials Oriented To Show Level, Plumb & 45 Degree, Vials Surrounds Are Molded, Black Abs Plastic For Better Contrast When Viewing The Vial, Rugged Aluminum Frame Resists Warping & Plastic Abs End Caps Protect The Frame, The Top Read Window Maximizes Readability.