3 Door relay install.
The customer had everything "prewired" but I guess their low voltage wiring guy forgot to wire the door jams with a wire for the door release latch. I installed 3 relays, that connect to the dial tones on their Cisco Router/ATA device and installed an e20B door phone at each door.
I left the coil of wire for the relay so that whoever was going to wire the door frames could just connect to that coil of wire. Everything has been pre-programmed for them so that they just need to run their wires and connect the door release latch.