Neewer Aluminum Screw Knob Clamp Arca Swiss Compatible Mini Quick Release Clamp with Hot Shoe Mount for QR Plate (38mm) features: cnc precision machining, surface anode anti-oxidation treatment, the body and washer is made of aluminium alloy and copper. compatible with all as quick release plate , such as rrs / arca-swiss / kirk / wimberley / markins / sunwayfoto / kangrinpoche / benro / sirui etc. when loose the screw, you can adjust the width of clamp. design of 3 strap buckles that make it more convenient to carry. specifications: material: aluminium alloy, copper color: matte black mounting thread: 1/4 length: 2.95"/75mm width: 1.5"/38mm height: 0.55"/14mm weight: 2.3oz/65g package contents: 1x screw knob clamp with hand strap gap