Extra strong light metal rectangular profile with gripping ridges & removable end-caps made from two materials. The removable end-caps are also equipped with well-proven patented anti-slip stops. 2 milled measuring surfaces, 2 vertical vials & 1 horizontal vial. Measurement accuracy: in normal position 0.029° = 0.5 mm/m, overhead measurement 0.043° = 0.75 mm/m. Length 1200mm (48 in) Plus 1 x 81S Scaffolders Level 250mm (10 in)