-Vapor works vertical feed
-Check it sweet spot trigger (flat)
-Revy(Hopefully soon to have a Halo TSA or an Egg II)
-Replaces stock piece of crap which means...
NO MORE STUPID ELBOW ! ! ! !
To me this is a perfect product, it does everything its supposed to do, I also give it a perfect 10 because its a perfect product. It also makes your gun look better. I also like the oring they put in the neck so your hopper stays nice and tight.
I would recommend this to anyone who wants to replace the elbow on your gun and give it a new look.