part 66040309 Piston Ø18 x 54 Interpump code 66040309 Details Interpump number66040309 DescriptionPiston Ø18 x 54 ItalianPISTONE D.18x54Qty per pump3 Fits these pumps Interpump 66 series 8 T3021T3025W3018W3021W3521W3523W4021WK5021