FORMAT: Compatible with DoorKing DK Prox READER COMPATIBLITY: These wristbands are compatible with the DoorKing 1815-333, 1815-330, 1815-305, 1815-302, 1815-301, 1815-300, 1504-124, 1815-305, and all 18815-xxx readers. SIMILIAR TO: DoorKing DK Prox DK Prox 1508-120, 1508-121, 1508-112, 1508-123, 1508-111, and 1508-129 cards and fobs. APPEARANCE: Blue Wrist Band: Internal diameter 65mm, Fits the average wrist size. INFORMATION WE NEED FROM YOU FACILITY CODE: Be sure to let us know what facility code you need. AuthorizID offers a wide variety of proximity technology. When purchasing from AuthorizID you are doing so with the peace of mind that you will also get free technical support to get your fobs programmed into your system from a team that has over 16 years of hands on experience with security systems and software. Not only are we here to help you program your products, but in the rare event that you purchased the wrong item we are here to guide you in the direction of compatible products for your system/software. FREE SAMPLES AVAILABLE: Not sure what cards/fobs work with your system? Contact us and request a free sample. You can do this by clicking the “Contact Seller” link on the far-right side of the listing in the “Seller Information” box. Leave us your name and shipping address and we’ll get some card samples and instruction on how to take advantage of our technical support team shipped to you absolutely free, no risk. Your sample will contain 3 different cards that have common formats. Odds are, we will get one of them working with your system. TECHNICAL SUPPORT- Receive free technical support programming your cards from our highly experienced technical support team. Not sure if this is right? We have free samples! THANKS FOR SHOPPING. WE LOOK FORWARD TO WORKING WITH YOU!