Expert Quality, with front viewing Plumb Site® Dual View™ vial. Aluminium box section extrusion electrostatically powder coated and baked with polyester acrylic paint. All have a milled base (except 1800mm). The 600mm has one horizontal vial and one Plumb Site® Dual View™ vial; the 1200mm and 1800mm has one horizontal, one plumb and one Plumb Site® Dual View™. Accuracy 0.5mm per 1M = 0.029° (1800mm 1mm per 1M = 0.057°) in standard position. Sold loose with display hanger.