The quality externally on this rail is superb, the aluminum gives it a nice and somewhat hefty feel to it, it really adds a lot to the look and feel of my G&G m4.
4 stars for not fitting, however its everything i imagined it would be.
though im not sure about the barrel because i used a madbull 6.03 in place of it.
Easy installation (tight fit on the G&G combat machines, it needed some sanding to fit correctly)
Doesnt quite fit right on the G&G combat machines at first, but with a little work it fits fine.
honestly, that is the only complaint so far.