Spindle-Mounted Indicator Holder Arm Arm Type Articulating Base Height 17/50 in Base Length 40 mm Base Size 40 mm L x 8 mm W x H Base Type Magnetic Base Width 8 mm Compatible Indicator Mounts 6 mm Fine Adjustment Position Fine Adjust Top (FAT) Maximum Reach 178 mm Working Length of Post/Lower Arm 56 mm Working Length of Snug/Third Arm 71 mm Working Length of Upper Arm 51 mm Base Thread Size M8 x 1.25 Construction Steel Includes Zinc Cast Fine Adjustment Includes Snug Yes