SafePort is an empty-chamber indicator for the M4/M-16/AR-15 rifle. Its purpose is to show at a glance and from a distance that the rifle's chamber does not have a cartridge in it. It is the only self-ejecting empty chamber indicator on the market, no extraneous motions are needed to remove it from the rifle. It is self-powered in that it has a spring that ejects it when the bolt is retracted about 1/4", or when a round is chambered (user's choice). It does not rely upon the bolt's extractor and ejector. SafePort cannot be put in place if there is an unextracted round or empty case in the chamber. It is also the only empty chamber indicator that acts as a dust cover. When in place, the bolt is held out of battery and the SafePort is visibly protruding from the ejection port, so (as with all empty chamber indicators) the dust cover cannot be closed, but SafePort is desgned to completely and effectively cover the ejection port when installed, keeping out dust and foreign material.
SafePort was designed mostly with the Patrol Rifle application in mind. Racked in a patrol car or other vehicle with a SafePort in place, visual verification of an empty chamber is possible, with no handling of the rifle being necessary. For those using a ceiling rack such as the Big Sky unit that positions the rifle with the ejection port up against the headliner or otherwise out of view, SafePort comes with an attachable yellow strip that can be seen from any angle, even when the ejection port is facing away from the viewer.
There is a textured area on SafePort where the serial number of the rifle can be written. This feature may be of help in reconstructing events by giving some indication of where a cetain rifle was charged.