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).