Bought this from a member here on the forums. I also bought the Madbull flash hider from another member here for my M4, but I thought it looked so good on the M9, I ended up purchasing another for my M4. Because I am new to the sport I had to do some research on howit operated. Once I got it gassed up, it was a blast to shoot. Haven\'t had a chance to do more than some target practice, but I am looking forward to the cooler weather to arrive here in Southern Louisiana so I can take it to the field. Thanks to everyone here for the great deals on parts and all the helpful advice.