Replacement end gear set for Hay tedders, fits First Choice and Galfre GS Series Hay Tedders, - GS250, GS300, GS400, GS450 and GS520 machines. The small gear has 15 teeth with a30mm bore with a key slot code 0037GS., the large gear has 22 teeth with the flange to mount the tine arm pan code 0064GS. These tedders have a square box housing and a bolt on lid that needs to be removed to expose the gears. These are used in the both the center and end baskets of the all GS series tedders.