Northwest Instrument NSL100B 20x Builders Level • 20x Builders Level • Magnification: 20x, with Stadia ratio (1:100) • Graduation: 1 • Working Range 200ft • Leveling Accuracy: 1/4 in @ 100 ft • Minimum Focus: 3.5 ft • Objective Aperture 22 mm • Sensitivity of Plate Vial: 8"/2 mm • Includes: Carrying case, plumb bob & manual • Tripod Adaptor: 5/8 x 11 thread