• True Blue vials are accurate to within 0.0005 per inch in all 10 level and plumb working positions • Heavy-duty 6061 aircraft aluminum chassis with 300 degree view top-reading level vial • Solid block acrylic vials won"t break,leak or fog • Milled edges foraccuracy with dual molded rubber endcaps for extreme shock resistance accuracy with dual molded rubber endcaps for extreme shock resistance • 3 Vials: 1Level/2 Plumb • Lgth In=48