Raven Concealment Systems TopStop Features The Raven Concealment Systems TopStop snaps onto most AR-15 or M4 type upper receivers once they are separated from the lower creating a sealed barrier over the open receiver. This seal keeps dirt dust and moisture from entering the action during storage or transport which matters when an upper is being carried loose in a bag or case. It equally prevents fouling and debris already inside the receiver from spilling out and creating a mess. Built from tough polymer the cover is designed to hold up to repeated use without cracking or losing its snug fit. Beyond sealing the receiver the TopStop also keeps the bolt carrier group and charging handle from sliding out of the upper as it is moved handled or packed away. This small detail prevents lost or damaged components during transport especially for shooters who break down their rifles for cleaning or storage. Finished in a matte Ranger Green that blends with tactical gear and cases the cover adds function without drawing attention. For anyone who regularly transports a detached AR-15 or M4 upper and wants to keep it clean and complete the Raven Concealment Systems TopStop is available for sale at GrabAGun. Raven Concealment Systems TopStop Specifications Manufacturer: Raven Concealment Systems Model: TopStop Type: Upper Receiver Cover Color: Ranger Green Compatible Hosts: AR-15 M4 Uppers Finish: Matte Available At: GrabAGun