Manfrotto 814-1 Hydrostatic Arm 5.1-Inch with 1/4-20-Inch and 3/8-Inch Threaded Pivoting Pins - Replaces 814 (Black)This Bogen Manfrotto 814 1 Hydrostatic Arm is the shortest arm at 5. 1 is also the most powerful. The pivoting pin is threaded with 1 4 20 and 3 8 studs so it can be attached to the top of a video camera to support a small monitor or other video accessory with an exceptional load of 7. 7 lbs. This arm also features a unique hydraulic lock that ensures no movement with the minimum of effort. This arm replaces the Bogen Manfrotto 814.