Colt style..... for the Bottom, Top, and Dedicated Adapters.
http://www.brownells.com/magazines/rifle-magazines/magazines/ar-15-m16-9mm-colt-style-magazine-prod38850.aspx
http://www.brownells.com/magazines/rifle-magazines/magazines/ar-15-m16-9mm-magazines-prod57092.aspx
The Brownells mag is made by Metalform and is less expensive. Anything not made by Metalform will be a quality of lesser degree.
