HIPA Carburetor with Adjustment Tool for Stihl FS40 FS50 FS50C FS56 FC56 HT56 HT56C KN56 KN56RC KM56 KM56C Trimmer 4144 120 0603 Replacement manufacturer part number: 4144 120 0603 Fits STIHL FS40 FS50 FS50C FS56 FC56 HT56 HT56C KN56 KN56RC KM56 KM56C Package include 1 carburetor, 1 adjustment tool Adjustment Tool is designed for Certified Technicians to tune carburetors, and keep engine within EPA specs