This nozzle is CNC machined from aluminum alloy EN AW 6012. Inside this nozzle is one sealing O-ring which stop loss of air during the shot and helps to increase FPS.Airsoft-Parts 20.4mm Nozzle £3.99PriceQuantity*Only 8 left in stockAdd to CartInstallation NotesThis nozzle must be used with an Airsoft-Parts Bore-Up cylinder, cylinder head and piston head. We recommend lightly lubricating the o-ring with Super Lube liquid silicone oil.