This Counterweight from Manfrotto is designed to attach to the pre-existing weight included with the 809 & 816 Salon Stands. The additional 4.2 lb added by the inclusion of this additional weight allows the stand to counterbalance heavier loads and create smooth vertical arm movements. Additionally, the weight is constructed of solid steel and features a 3/8"-16 male connection screw for securely attaching to the stand's original, integrated counterweight.