Westward Magnetic-Base Indicator Holder 2YND8 Magnetic base indicator holders that have a magnetic base connected to an adjustable arm assembly, which is used to mount and position indicators. These devices are also known as mag bases and can be permanently on or have an on/off knob or button for easy mounting on machines, motors, benches, or other metal surfaces. Arm Type / Rigid Base Height / 2-1/8 inch Base Length / 2-1/2 inch Base Size / 2-1/2 inch L x 2 in W x 2-1/8 in H Base Type / Magnetic Base Width / 2 inch Compatible Indicator Mounts / 3/8 inch Holding Power / 85 lbf Maximum Reach / 15 inch Step Type / V Step Working Length of Post/Lower Arm / 9.25 inch Working Length of Snug/Third Arm / 15 inch Working Length of Upper Arm / 14.5 inch Base Thread Size / M8 x 1 Construction / Steel Includes Snug / Yes Magnet Type / On/Off Knob Screw Type / Plastic Knob