Replacement vertical gear for Hay tedders, fits First Choice and Galfre GS Series Hay Tedders, - GS250, GS300, GS400, GS450 and GS520 machines. This gear has 22 teeth with a flange with 4 threaded holes for the pan to mount that holds the tine arms. The axle assembly mounts to the shaft (not included) that runs through this gear. These tedders have a square box housing and a bolt on lid that needs to be removed to expose the gears.