SSR4 Barrel Nut
A spare barrel nut for metal or plastic handguards.
This part allows you to install a metal SSR4 handguard to a plastic SSR4 and a plastic SSR4 handguard to a metal SSR4.
You can install the SSR4 handguards on most M4 style replicas by using the appropriate barrel nut.
It is not possible to connect the barrel nut for the metal handguard to the plastic handguard and same goes for the opposite.