General Technologies Corp GTC TA100 Smartach+ Wireless Ignition Analyzer and Tachometer Special antenna sensor allows quick hook-up to spark plug and ignition coil wires and measures spark plug wire voltage from 0 to 50000 volt For 1 to 12 cylinders and 2, 4 cycle and DIS engines Measures from 200 to 20000 RPM on a 4-1/2 digits LCD display Advanced microcontroller technology yields 0.05 percent accuracy Works on DIS, conventional, magneto and most spark ignition system