TP-DCDC-12xx DC to DC converters take an input of 9-36VDC and convert to 18V, 24V or 48V DC regulated output. They include an integrated POE inserter to apply the DC voltage to the CAT5 cable on Pins 4,5 (V+) and Pins 7,8 (V-). They are perfect for running POE powered equipment from a 12V or 24V battery system. They have 2 isolated inputs to handle two power sources like a primary and backup source for uninterrupted failsafe operation.