The Manfrotto 244N variable friction Magic 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. Both ends feature a 5/8" baby pin. One end has a female 1/4"-20 threaded receiver, the other has a 3/8"-16 threaded receiver.