[G&G arp 556 handrails/railsystem]

Some barrel nuts have imperial and some have metric threads. You occasionally read of people having to rethread the receiver to fit an incompatible nut. Hopefully with a search you can find out what you have, and hopefully whoever is selling what you want provides the correct information. There's a lot of hopefully's with fitting parts in airsoft.

 

Edit to add I'm assuming it's airsoft M4 spec. 

https://miairsoft.proboards.com/thread/23328/m4-barrel-nut-specs

[Seeking opinions on the various "spitfire" tracer units available]

14 hours ago, Enid_Puceflange said:

I have the version that Amazon is showing (bought it from eBay)

I also think these are the very same item , just packaged differently

the only thing I don’t like is the inability to have just the muzzle flash on its own. I run mine on my gbbr and like the flames from the muzzle effect, though you cannot switch off the tracer function. 
 

Reasonably well made piece of kit, which I anticipate it getting rattled to death and failing using it on my Ghk.

Would like a better style to it, making it look more like a muzzle break than a small suppressor 

my mate shooting my ghk for the first time, and sweary 😂

 

I see a few vids where the gun obviously fires but no flash, is that just the frame rate of the camera missing the flash every now and then?