Postal sorting line: Listen & Download Postal sorting line .mp3 Error! Change your browser, please! ⇓ Download The atmosphere of the factory, rattling ⚠ Factory atmosphere, drone in a mine tunnel ⚠ Spinning machine ⚠ Off, Forklift, on, standby ⚠ Welding transformer operation under load ⚠ Steam pump ⚠ Oil pump ⚠ Gas welding ⚠ Hydraulic activator ⚠ Spectrograph ⚠ Power station turbine ⚠ Mill for grinding grain, Brewing unit ⚠ ★★★★★