They are the G&P ones and are not as good as the normal ones IMHO but I have a habit of setting the ones without caps off accidently (there's a funny storey with a can of coke that exploded in my face because of moscarts:))
The stock is fantastic both build quality and function and the weight saving over the para stock is nice to have. If you find the para stock a bit long when extended I would definitely recommend this one.
Sorry dude not an ACM one.