HIPA (Pack of 2) Pre Filter with Air filter Cleaner for STIHL FS75 FS80 FS85 HS75 HS80 HS85 Trimmer Replacement manufacturer part number: 4137 124 1500, 4137-124-2800 Length 2-3/8" x Width 2-3/8" x Thickness 1/4" Fitment models: STIHL FS75 FS80 FS85 HS75 HS80 HS85 trimmer Qty: 2pcs pre filter + 2pcs air filter