The SSAIRSOFT Barrel Cover will fit over the barrel of most airsoft guns. The SS Barrel Cover will also fit over most mock suppressors. A barrel cover is excellent for transporting airsoft guns; not only does is protect against accidental discharge, but it will protect other players from a stray BB round. This model requires you to strap the bungee cord around the gun after covering the barrel. This will help in preventing the barrel cover from falling off during transportation. Some fields require players to transport their airsoft guns with a barrel cover attached. Safety is the number one priority and should be practiced in airsoft. Thanks for being safe.