These AR 15 rifle kits contain all components to Build YOUR Rifle. Our AR-15 Rifle kits are available in different calibers. Some Calibers include .223/5.56, 300 blackout, 7.62 x 39, 9mm and 6.8 spc. The AR15 Rifle kit Upper Receivers with the kits come in a variety of Barrel Length options. Also we carry a choice of 416R stainless steel or 4150 steel with Nitride finish on Barrels. These Rifle kits can also have numerous length Handguards and a variety of color finishes. Available in keymod, m-lok, or quadrail Mounting Systems. Lengths of Handguards on the AR-15 upper include 7" - 10" - 12" - 15". Wide Selection of colors to choose from on your AR-15 upper receiver and handguard. Daytona Carries Black, Flat Dark Earth, Burnt Bronze, OD Green, Zombie Green, Tungsten Grey and Titanium Blue.