Postal sorting line: Listen & Download Postal sorting line .mp3 Error! Change your browser, please! ⇓ Download Spectrograph ⚠ Notches, print imprinted in cardboard ⚠ Lithographic press ⚠ Oil pump ⚠ Forklift approaching ⚠ Small centrifuge ⚠ Hydraulic pump ⚠ Power station generator ⚠ Signal for lunch at the factory ⚠ Bottling plant ⚠ Box making machine ⚠ Rattling, The atmosphere of the factory ⚠ ★★★★★