Allows quick, accurate reads even in the darkest, most cramped situations; powerful LED lights provide illumination in all 3 vials and automatically turn off after 10 minutes.Features: continuous dual rail frame; .029 degree vial accuracy; precision machined; vial lighted system; supershock end caps; 80 percent stronger "Savage" strength frame; acrylic block vials; multi-ring vials; 300 hour average battery life.Included in box: Swanson SVLB24 60cm lighted box beam level and (2) Energizer batteries.