This compact bevelled shaped level has a die-cast aluminum body which makes it one of the sturdiest levels that STABILA makes. This level is for all those who need both hands free when aligning and levelling on steel frame structures. The 81 SM Torpedo has a rare earth magnet system with strong holding-power. The vial is precisely aligned with the milled measuring surface then locked together. This gives you years of accurate levelling. STABILA TYPE 81 SM 10″ DIE CAST MAGNETIC TORPEDO LEVEL