Knights RIS. replaces the standard hand guards on 9mm and 5.56 light weight carbine barrels. Installation takes about 5-10 minutes and requires no tools. Picatinny rails on all four sides allow endless possible mounting solutions for accessories such as sling mounts, vertical forearm grips, flashlights and more. The R.I.S. comes with three 11 rib panels to help protect the rails from battle damage.