The Kupo Junior Boom Arm is made from solid steel with a black coated finish that can support a payload up to 88.2lbs (40kg) at minimum extension and up to 22lbs (10kg) when fully extended. The heavy-duty tilt locking device is designed to be used with a 4-1/2" Grip Head (such as the Kupo 4.5" Grip Head with Junior 1-1/8" Stud and Receiver - KG400512) with the T-slot ear to provide the ability to tightly lock and for allowing the boom to slide within it to adjust for load balance. The heavy-duty steel hook is also welded on the end of the boom for hanging a counter weight. Caution: Always ensure the proper balance between your lighting fixture and counterweight on the boom.