Knight's Armament M249 RAS Installation takes about 5 minutes and only requires an allen wrench. Picatinny rails on three sides allow endless possible mounting solutions for accessories such as sling mounts, vertical forearm grips, flashlights and more. The M249 R.A.S. comes with three rail covers to help protect the rails from damage. Bottom rail cover is cut out to allow bipod to clip into it for storage.