The Stabila 81S Torpedo Level has a strong cast aluminium T-profile making it easy to hold. The particularly slender trapezoidal bevelled shape makes it suitable for working in cramped spaces. The die-cast frame has 1 milled measuring face and protecting noses to prevent damage to milled face. Additional magnets mounted in the milled measuring surface hold this level securely on scaffolding or beams. 2 Vials 1 plumb & 1 horizontal. Accuracy Normal Position 0.029=0.5mm/m. Accuracy Overhead Position 0.043=0.75mm/m. Type 81SREM has rare earth magnets (five times stronger).