The SC Series Testers provide rapid, positive testing for multiline speaker cables. Rotating the central switch applies voltage to the cable conductors one at a time. A SEND LED indicates the pin to which the voltage is being applied, and a RECEIVE LED indicates where it returns. This system clearly reveals, shorts, opens, and cross-wires, allowing you to test common combinations of speaker cables. The SC48 (NL or EP) tests 4 and 8 pin cables, and the SC46EP tests 4 and 6 pin EP cables. All three models also test 3-pin XLR cables. 9V battery required.