The Manfrotto 244N Variable Friction Magic Arm differs from the regular Magic Arm, in that the Variable Friction Arm allows partial locking in place of a light, grip, or a camera. This comes in handy when using a light or camera to track a subject. It is a pivot arm with a large locking knob. One end will support a light that has a baby (5/8") receptor. The other end is designed to fit into a Super Clamp socket, or other 5/8" receptor. The Variable Friction Magic Arm is modular -- Stand it on the floor or a table with an optional Backlite base (3095). The Variable Friction Magic Arm is modular -- Lock it into an optional Super (2915), or Maffer Clamp, on a pipe or shelf from 1/2 - 2" in diameter or thickness. The Variable Friction Magic Arm is modular -- Use it to mount a camera with the optional camera bracket (143BKT), or order #2929 which includes a camera mount, or #2930QR, which has a Quick Release Camera Plate.