[Material]: The strut is made of aluminum and the base is cold drawn steel. [Size]: Fixed arm height: 6.9"; Extension arm length: 6.3"; Magnetic Base dimension: 2.30" L x 1.98" W x 2.18" H; Holds 3/8" stem and lug back; Holding Power: 135lbs. [Magnetic base]: The magnetic bracket adopts switchable permanent magnet, which is easy to install on the metal surface. V-groove base for easy installation on cylindrical parts. [Universal knob]: Flexible, strong and precise rotary joint can adjust the support rod to any direction and fix it firmly. [Application]: Used to maintain the position of a dial indicator or test indicator etc. during measurement operations.