Mini Magnetic-Base Indicator Holder Arm Type Mini Post and Snug Base Height 1 in Base Length 1 3/16 in Base Size 1.18 in L x 1.18 in W x 1 in H Base Type Magnetic Base Width 1 3/16 in Compatible Indicator Mounts 3/8 in 8 mm Dovetail Mount Holding Power 30 lbf Maximum Reach 4.17 in Step Type Flat Working Length of Post/Lower Arm 4.17 in Working Length of Snug/Third Arm 0.5 in Working Length of Upper Arm 4.17 in Base Thread Size 1/4 in-20 Construction Cast Iron Includes Snug Yes