It's a stock - Reptilia RECC E Stock for AR15/M16 Carbine Length

Unfortunately, while it does have a unique look which I like- it's largely useless. It doesn't do any one thing well, except maybe being more compact while collapsed. You can tell it's a little bit of a ripoff UBR stock, but significantly less rigid while definitely being lighter. When extended, because it is completely polymer - it flexes dramatically while pulling the stock into your shoulder. If you run it one click in it is significantly better, but then you have a very short LOP. The QD cups are nice, but most any other stock for 1/3 the price includes those. Not worth the money, unless you just want the look.