Datamars RFID T-SL Slim microchips come in both USDA 840 and Standard 966 version that does not require a premise id number to order. Both give Equine/Deer/Elk permanent and unique identification. Implantation with thin,14 gauge needle. The Datamars T-SL Slim microchip cannot be falsified or changed. Each is as small as a thin grain of rice, weighs a fraction of standard glass microchips and contains a permanent ID code that is unique to that animal.