Carburetor replaces Zama C1Q-S186. Fits some Stihl Models: FS38, FS45, FS45C, FS45L, FS46C, FS46, FS55, FS55C, FS55R, FS55T, FS55RC, HL45, KM55, KM55R, FC55. Replaces Stihl 4140 120 0619. May also replace Zama C1Q-S97, C1Q-S186B, C1Q-S66, C1Q-S71, C1Q-S97A, C1Q-S143, C1Q-S153.