48 inches, Aluminum Box Beam Level, Three Vials Read Plumb, Level. Johnson Surround View Vials Reflect Ambient Light For Easy Read. Solid Block Acrylic Vials Won't Fog, Leak Or Break. Impact Resistant ABS End Caps For Durability. ABS Hand Grips For Comfort. Accuracy Up To.029 Degrees 0.5 mm/m) In The Standard Position..044 Degrees 0.750mm/m) In The Inverted Position.