Spec Sheet Preview: The Alpha Communications® / TekTone OF19_ (flush) and OF19_S (surface) series entry panel frames are made of heavy gauge extruded aluminum, in a natural (clear) anodized finish. Both types are used with a variety of apartment entry intercom and video intercom lobby panel modules, alphabetical directory modules, as well as specialty and annunciator modules. The 19" height on the OF19_ (flush) series is ideal for mounting alongside standard 19" high vertical mail boxes, if requir …