The DoorKing 1504-124 is a DK Prox Card Reader with Intercom Substation and surface mount enclosure. This kit using the Proximity Card Reader 1815-300 which has 3" read range. These card readers output their data in 26-bit wiegand format. Thr card eeaders operate on 12 VDC, 200mA. These card readers are not designed for stand-alone operation and must be connected to an access controller (DKS 1830 Series systems).