47" (1200mm). Ultra-rigid aluminium profile with ribs that reinforce the strength. The vial, the block holder and the measuring surfaces are adjusted and aligned precisely to one another. With 3 vials; one horizontal and 2 plumb. Capable of measuring in normal and reverse positions. Removable shock-absorbing end caps with anti slip grips, enables level to work right into corners. With anti-static and UV-protected vials.