STARRETT 657AA Magnetic Base w/Attachments,Rod 0.250 In 2ZUL3
Magnetic-Base Indicator Holder, Arm Type Rigid, Base Height 1 15/16 in, Base Length 1 7/8 in, Base Size 1 7/8 in L x 1.625 in W x 1 15/16 in H, Base Type Magnetic, Base Width 1 5/8 in, Compatible Indicator Mounts 1/4 in, 3/8 in, Holding Power 100 lbf, Maximum Reach 12 in, Step Type Flat, Working Length of Post/Lower Arm 7.5 in, Working Length of Snug/Third Arm 2 in, Working Length of Upper Arm 6 in, Base Thread Size 1/4 in-20, Construction Cast Iron, Includes Snug Yes, Magnet Type On/Off Knob.