Rotary Corp brand aftermarket product. Replaces 0000 997 1501 Spring for Rotary 27-14073 Head. Replaces Autocut 25-2 Replacement Spring. Replaces Models FS 44, 55, 80, 83, 85, 90, 100, 100RX, 110, 120, 130, 200, 250, KM 55, 85, 90, 110, 130, & FS-KM.