The Amoeba Sound Suppressor Barrel Extension (Short version) is a black mock suppressor. This is a unique product, in that it will fit directly on to your M4 flash hider! It will only work on M4 flash hiders that have a large type threading including orange ones. Guns we've test: Amoeba (works on all models), G&G Combat Machine SR series (Keymod guns), Sportline SCAR.We're quite impressed with the compatibility with the G&G SR series' orange flash hiders. You just screw it on for a direct fit!Note: This doesn't actually decrease the sound of your AEG. Do not use on real guns, it will cause harm. This is not a power up adapter. You can use a longer inner barrel with this extension.