AISEN (Pack of 3 Replacement Air Filter for STIHL FS50 FS56 FS70 FC56 FC70 KM56 Trimmer Brush Cutter # 4144 124 2800 Replacement manfacturer part no. 4144-124-2800 Fit models: stihl FS40 FS40C FS50 FS50C FS50-L FS56 FS56R FS56C FS56RC FS70 FS70C FS70RC FC56C FC70C KM56 KM56R KM56C KM56RC HT56C trimmer Qty: 3pcs