HIPA Spark Plug + Fuel Filter + Air Filter + Primer Bulb for STIHL FC55 FS38 FS45 FS46 FS55 HS45 KM55 HL45 String Trimmer Brush Cutter 4140 124 2800 Trapezoid air filter, replacement manufacturer part number: 4140 124 2800 Fitment models: STIHL FC55 FS38 FS45 FS46 FS55 HS45 KM55 HL45 string trimmer Package include: 1 x spark plug, 1 x primer bulb, 1 x fuel filter, 1 x air ilter Won't fit STIHL FS76 and FS85 which use a rectangle shape air filter