Stens 085-2257 Pro Spur Sprocket Replaces: Echo: 17510514630, 17511412530, A556000020, A556000021 GB: ec206-j7n Oregon ref.: 513444 ref no: sec206-27n Fits Echo: CS-3600, CS-3900, CS-400EVL, cs-440, CS-4400, CS-440EVL and CS-5100 John Deere: 45 Bearing included