This Manfrotto Variable Friction Magic Arm with Camera Bracket features a large center locking knob. Variable friction and locking of arm obtained by adjusting knob. Comes complete with Camera/Umbrella Bracket 143BKT only. This replaces the Manfrotto 2929. Arm length: 20.87 in.; arm tube diameters: 20mm.; attachment: type 17; attachment 2: type 17.; color: black; load capacity: 6.61 lbs.; material: aluminum; weight: 2.40 lbs.