Rack Mounted Panel Telephones have found widespread use in central offices, data centers, large industrial communication facilities and earth satellite installations. Such varied applications and field experience have resulted in the continued expansion of available models, while state-of-the-art advances have resulted in improvements of our older designs. By referring to the associated Ordering Information Chart, the representative photographs and line drawings that follow, the flexibility offered the user is readily apparent. Units are available for horizontal, vertical or surface mounting on 19 or 23 inch racks. Other variables include single or multi-line, pulse or tone pad (dial), headset or handset, ringer or buzzer, level or cradle hookswitch, etc.