Rewind spring/Recoil spring Genuine Stihl Part OEM Part No. 4140 190 0601 Suitable for the Following Applications: HL45, FS38, FS45, FS45C, FS45L, FS46, FS46C, MM55, MM55C, FS55, FS55C, FS55R, FS55RC, FS55T, KM55, KM55C, KM55R, KM55RC, FC55