carbon fiber which is very strong, lightweight & portable Can be installed on top of tripods, monopods, phone mounts and light stands and other equipment 4 types for your option: 33 / 29x237mm, 29 / 26x236mm, 26 / 22x235mm, 22 / 19x234mm / 4 " to 3 / 8 " Bushing Adapter, fits the tripod, stabilizers and camera accessories with 1 / 4 " or 3 / 8 " mount Extend the height of the tripod, and use