Dust Doors on the AR-15/M16 platform are a barrier between the action and the elements, under constant spring pressure, the action of the bolt carrier reciprocating or being manually cycled the dust door will open up allowing ejection out of the door. During travel, the dust door can be closed and held in place with a captive detent holding it against a groove cut out in the upper receiver. Typically made from the same grade of aluminum that the upper receiver is made from, dust doors are a great way to protect the internals of your build!
About this Dust Door: The Timber Creek Outdoors Greyman Billet Dust Cover is adjustable to ensure it securely fits any mil-spec uppers and ejection port. It can also fit into most billet uppers. This high-strength dust cover is made from aircraft-grade aluminum and comes with everything needed for installation.
Material: Aluminum - This dust door is made from the same aluminum found on the upper and lower receiver of an AR-15.
Compatibility: Standard Size Upper Receiver Door
Color / Finish: Black Type III Hardcoat Anodized Color