The SmallRig Holder for Portable Power Banks is made from aluminum alloy to be lightweight yet strong. Its design allows you to mount portable power banks (USB batteries) to your camera so you can power it for extended periods of time. It features multiple 1/4"-20 threaded mounting holes so you can position it where it works best for you. The clamping jaws are lined with rubber pads which protect the finish of your power bank. The entire holder weighs in at only 3.7 ounces, so by itself it won't significantly add to your rig's weight.