plumbsite® box section levels expert quality, with unique front viewing plumbsite® vial. Aluminium box section extrusion electrostatically powder coated & baked with polyester acrylic paint. All have a milled base (except 1800mm). The 300mm & 600mm sizes have one horizontal vial & one plumbsite® vial; the 900mm & 1200mm sizes have one horizontal, one plumb & one plumbsite® vial & the 1800mm has two horizontal, one plumb & one plumbsite® vial. Vial. Accuracy 0.5mm per 1m = 0.029° (1800mm 1mm per 1m = 0.057°) in standard position. Manufactured for draper tools by kapro. Sold loose with display hanger..