This is a Miner John Designs 20″, 4 pin power cord that works on Minelab SD and GP Detectors, 2100, 2200, 3000, Extreme and 3500 models. It is designed to work with the after market Coiltek ” Pocket Rocket” and other similar style battery systems.
Built to be very solid and hassle free. Light yet super strong, and you do not want to be out hunting and have the stock coiled cord go bad without a backup. Makes the perfect full time power cord or keep it in your pack as a spare. Either way they are nice!