Aluminum alloy frame thickness 3 pcs of acrylicl vial,toerance of accuracy milled finish datum plane with2 magnet Aluminum alloy frame thickness=0.7mm power coatedd,3 pcs of acrylicl vial,which is combine level vial and indicate level,plumb and 45,toerance of accuracy0.057°=1mm/m.milled finish datum plane with 2 or 4 magnet. 96B-M