The Stabila 81S Torpedo Level with 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. Specification 2 Vials: 1 plumb and 1 horizontal.Accuracy: Normal Position: 0.029°=0.5mm/m.Accuracy: Overhead Position: 0.043°=0.75mm/m.