The Alpha Communications®/Tektone Tek-Guard Series modular aluminum directory units are designed to mount right on the surface of the wall. Made of heavy-duty extruded aluminum, the Tek-Guard directories hold up to 60 engraved (or blank) directory strips in each AM190D directory module, protected by a polycarbonate window. For installations requiring more than 60 names, simply mount additional AM190D directory units side-by-side in a larger OF190 series directory frame. Installation is quick, easy, attractive and requires no back box. Name insertion and maintenance requires the use of a Scrulox type screwdriver (model S1). The use of Scrulox head screws makes it nearly impossible to open the directory without the use of the special tool (soldseparately). The engraved strips are held in place by an extruded aluminum track, with a 'stop' on the bottom to prevent names from falling out, once installed onto the frame. The Tek-Guard directory units can be used in conjunction with lobby entry intercom panels, or as a stand-alone directory installation, for mail boxes or other installations. Directory strips can easily be inserted into the model AM190D (60-name capacity) directory modules using optional engraved plastic directory strips (model #TDS) and fill-in directory blanks(model #TDS-B). All Tek-Guard directory units require one (or more AM190D) directory modules and an OF190 series directory frame.