Starrett 98Z-12 Precision Machinists' Level in Finished Wood Case, 12" Length 12" precision machinists' spirit level with a main vial and a cross-test vial for determining horizontal plane and a plumb vial for determining vertical plane Graduated, ground glass main vial has a sensitivity of 0.42 mm/m or 80 to 90 seconds and is adjustable to a positive setting for accurate results Cross-test vial enables simultaneous leveling in two directions V-shaped groove along the base provides reliable seating when leveling round items Cast iron base for durability and finished wood case for storage Cross test vial allows simultaneous leveling in both directions. Plumb vial is adjustable Ground and Graduated main vial Made from the finest quality seasoned cast iron Precision machined on the reference surface Includes finished wood case