Articulated arm. Features as 143N, but a large locking knob takes the place of cam-lever. Variable friction and locking of arm obtained by adjusting knob. Specifications: Arm Length: 20.87 in Arm Tube Diameters: 20mm Attaches By: type 17 attachment type Attachment (Top): type 17 attachment type Color: black color Material: aluminum Load Capacity: 6.61 lbs Weight: 2.4 lbs