This is a small junction box complete with a 12vdc power adapter.

The adapter plugs into the power jack on the side of the junction box and a 12v device can then be wired to a terminal block inside to run 12vdc devices such as wired infrared beams dialers etc.

The 24vdc relay inside is triggered by 24vdc and 12vdc will pass through the contacts to trigger 12vdc devices.