- The ProMaster 5151 Illuminator Arm is a tool for holding many types of reflectors, boards, and backgrounds. It can can be mounted to a light stand either by its sliding center collar, or by its brass 5/8" end spigot. A tilting / swivel mount is included so the Illuminator Arm can be adjusted and maneuvered easily. The strong, large spring clips can be moved along the arm to various positions, allowing them to hold a range of different sized reflectors and backgrounds. The Illuminator Arm works with pop-up reflectors & backgrounds, foam boards, and cloth backdrops.