Levels have ground and graduated main vials. All levels have cross test vial. 18" size has a double plumb vial. Plumb vials on 18" levels are ground. Main vials are adjustable for positive setting and housed in a satin-chromed brass tube with friction fit closing cover to prevent breakage. Level base are of the finest seasoned castings with black wrinkle finish, accurately machined and finished on bearing surface. An involute longitudinal groove between bearing flats provides accurate seating on round work.
