Use the USB RFID Reader to program your RFID cards and FOB's. Grandstream GDS37x0-RFID-RD is a 125 kHz RFID card reader designed for use with the Grandstream GDS3710 IP Video Door Phone. This unit plugs into any computer running Grandstream GDS Manager software, enabling full management including tracking and monitoring of the secure RFID card system. It is powered through the USB cable. Plug the USB Reader into your PC and easily program your RFID Cards and FOB's. Features - USB Connectivity - RFID Frequency 125 kHz - Power DC 5V (through the USB cable) - Operating Distance 0-40 mm - Dimensions 4.27' x 4.27' x 0.94'