The 5104 has 4 input zones, an auxiliary bell circuit (alarm, trouble, or dialer active), and programmable relays. Note: This is the older 5104, not the 5104B. Cabinet had labels and other stains on it, but is in good physical shape.
Easy to install and program (if you have the programmer) Accepted by most fire jurisdictions. Mine had parts missing, the battery cable and reset button.
This is the best dialer panel out there. It is easy to install, easy to program, and works well with the new cell dialers.
Great find for a great product