It is based on para platform. So grip is a little bigger than 2011. It has a lot of sharp edges that need to be smooth out. For it's price,it's a good project gun if you like diy. I don't think it work very well without any change.
Cheapest option is vortex or burris, better one is leupold DPP which has better build quality. Rmr is too small for competition, good for Carry Sent from my SM-G955U1 using Tapatalk