Ground and graduated main vials The base of the levels features an involute groove running the length of the base, which provides a reliable seat for round work Cross test vial The vials are adjustable to a positive setting and are housed in a satin fi

Ground and graduated main vials
The base of the levels features an involute groove running the length of the base, which provides a reliable seat for round work
Cross test vial
The vials are adjustable to a positive setting and are housed in a satin finished brass tube with a friction-fit closing cover to prevent breakage
Main level vials have graduations that are approximately 80-90 seconds or .005" per foot (0.42mm per meter)