98 Series Machinists'' Improved LevelHave ground and graduated main vials. These 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. The base of the levels features an involute groove running the length of the base. With the cross test vial, it is possible to simultaneously level in both directions. Accuracy: 0.005 in @ 1 ft; Base Type: Grooved; Body Material: Cast Iron; Length: 6 in; Number of Vials: 2; Type: Machinists' Level; Vial Positions: 2 Level; Weight: 0.94 lb.