Die-cast aluminum frame. Ideal for electrical, pipe fitting, mechanical, millwork, drywall, and other applications. 4 flush mounted magnets for greater convenience. Vial accuracy of .029 in vial-up position. 1 vertical and 1 horizontal crystal clear, nonfogging unbreakable, monoblock, acrylic vials. Each Stabila level is electronically adjusted. Machine milled faces assure measuring accuracy. Unbreakable, acrylic vials won't break, leak, or fog for life. Top and side reading in both vial-up and vial-down positions for best accuracy. Sure-grip anti-slip wall pads. Slip-resistant. Yellow electrostatic epoxy coating for high-visibility and resistance to mortar adherence and corrosion. Patented epoxy system, locks vials into the frame for no loss of accuracy and never readjusting.