HIPA (Pack of 2) Air Filter Fuel Filter Primer Bulb for STIHL FC55 FS38 FS45 FS46 FS55 HS45 KM55 HL45 String Trimmer Fitment models: STIHL FC55 FS38 FS45 FS46 FS55 HS45 KM55 HL45 string trimmer Fuel filter use a 3/16 Package include 2pc air filter, 2pc fuel filter, 2pc primer bulb