Airsoft Silencer (G&G M4 Combat Machine)

This is a silencer for the M4 Combat Machine (airsoft) by G&G.
Unscrew the current cast iron barrel. And plug this silencer in its place - it runs from the picatinny rail all the way to the barrel tip.
Total length is 173mm (excluding a section then goes into the picatinny rail gap, for stability)
Inner hole is diameter 9mm (1mm more than most inner barrels)
Outer Diameter is 38mm (same as the ring inside the picatinny rail)
The outer section that plugs into the picatinny is 20mm outer dia