The AvengerF831 Baby Female Swivel with Ball can convert an arm or dowel up to 5/8" in diameter into a boom arm. It can add versatility to your non-swiveling light fixture (with optional #013) to make it more versatile.
Each end has a locking Baby 5/8" (16mm) receiver. The ball joint has a pull-and-lock aluminum alloy handle with anti-rotation springs. It weighs 1.76 lb (0.8 kg).