I ordered a kit that came with a upper +parts kit, lower +parts kit, and a fortress defense systems free float hand guard + barrel nut, wrench, hardware, and 2 small rails (besides the full top rail) all for $260 originally $420. I couldn't find any info on the fds handguard before I ordered and was told they are a defense contracter that white wolf (aero partner) does business with and they don't sell commercially so that's why I couldn't find info on it. I'm very impressed with it, looks and feels like a quality handguard and nice and light like I wanted but my only problem is that the 2 small rails it comes with install by removing small bolts from the sides or bottom and screwing them in but I have no idea where I'm going to be able to find more. Was wondering if anyone has experience with FDS or has the same kit and knows where or what to purchase. Thank you!