help ID'ing a mystery china ar stock

[greyling22]

my wife is down with the flu so I am playing nurse and stuck bumping around the internet.

So this stock is from china, and probably for airsoft only, and most likely a copy, but what is it a copy of? http://www.aliexpress.com/item/Gun-...Vltor-004-Black-Free-Shipping/1578999542.html

I don't see anything like it on daniel defense or vltor's sites.

The reason I ask is because it looks like the structural support that protects the release comes off or performs some sort of trick and I can't figure out what it is.

here it is in a different color. http://www.aliexpress.com/item/Gun-...Vltor-Kahki-004-Free-Shipping/1578956183.html

 

[Eureka40]

I'd say magpul.

http://store.magpul.com/product/MAG400/180