NAC Power Extender - 24VDC @ 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, 1 amp aux. output, red encl. 15.5inH x 12inW x 4.5inD, 115VAC in