Gray Ops CNC AR15 Chamber Flag Black. Prevents mags from being inserted unless the flag is removed and the ability to add a chiller on those hot days. Specifications for Gray Ops CNC AR15 Chamber Flag: Manufacturer: Gray Ops CNC Color: Black Last Chance: Yes Features of Gray Ops CNC AR15 Chamber Flag Ensures that there is no round in the chamber. EASY One hand insertion and removal. Package Contents: Gray Ops CNC AR15 Chamber Flag Gray Ops CNC GO-8015-AR15: AR15 Chamber Flag Black