Portable Mini RJ45 RJ11 Cat5 Network Ethernet LAN Cable Tester Efficient scan for the miss wiring, disorder cable, open and short circuit as well as crossover circ 9 LEDs to indicate which wire whether open or not on both remote and master unit Switch on button available Powered by DC 9V terrace battery (not included ) Connector: 2 x RJ45 & 2 x RJ11