Abstract: A telescoping mast assembly for floodlighting equipment or other apparatus is arranged to be raised by admitting pressurized fluid to the interior of the assembly and lowered by releasing the fluid. The assembly is constructed of light metal, such as aluminum alloy, and includes a plurality of telescoping hollow members, or tubes, each inner member having a pair of substantially spaced wear rings near its lower end for maintaining the spaced positions of the members and a fitting at its outer end carrying an internally mounted wear ring for maintaining the spacing at the outer end. The telescoping members do not engage one another but are spaced by the wear rings. The fitting is readily detachable and facilitates the use of straight lengths of standard aluminum tube stock for the mast sections. The fittings include keys slidably engaging longitudinal slots in the members for preventing rotation of the members with respect to one another. Seals are provided for preventing leakage of fluid between the members.