Innovative modular system Supports up to 17.6lbs (8kg) Many interchangeable accessories available - ideal for use with a convi-clamp Single knob secures both ball joints simultaneously Constructed from aluminum alloy The Kupo Super Knuckle System is an innovative modular system that features a double-ended shell that accepts two ball joints mounted to interchangeable accessories on either side. The shell has a single knob in the center to tighten both ball joints simultaneously and complete freedom to position accessories anywhere. The Super Knuckle with Hex Baby Pin can support up to 17.6lbs (8kg) and includes the shell with a hex baby (5/8in) pin on one side for attachment to accessories like convi-clamps, and a locking thumb wheel with a 1/4in-20 male thread on the other for cameras or other gear with female 1/4in-20 threads. Specifications Weight: 0.95lb / 0.43kg Color: Black Product Height (in): 1.23in Product Height (cm): 3.12cm Product Length (in): 5.63in Product Length (cm): 14.3cm Product Width (in): 2.37in Product Width (cm): 6.01cm Product Weight (lb): 0.95lb Product Weight (kg): 0.43kg Maximum Payload Capacity (lb): 17.6lb Maximum Payload Capacity (kg): 8.0kg Primary Material: Aluminum Warranty: Limited Two-Year Warranty