NAC Power Extender - 24V DC @ 10 amp. 2 - Class A or 4 - Class B NAC circuits, operates 2-wire Horn/Strobes, generates Cooper/Wheelock, System Sensor, Gentex, Faraday & Amseco sync protocols, two - 1 amp aux. output, red encl. 15.5"H x 12"W x 4.5"D, 11 5V AC input, UL Listed Fire (UL864/UL1481), MEA, CSFM & FM Approved.