Stihl Service Kit 31 for STIHL BT 131, FR 131, FS 131, FS 311, HT 130, HT 131, HT 133, and KM 131 machines simplifies maintenance to enhance performance and extend the machine's lifespan. It includes a paper air filter, spark plug, and fuel filter, ensuring optimal engine efficiency, reduced fuel consumption, and easy starting. Integrated tools make replacement quick and easy.