The WEGO IV series are stand-alone units with built-in data logging intended for automotive under dash or dyno environments:  Both WEGO IV units are identical except that the dual channel unit displays and logs two channels of air/fuel (AFR) data  Complete AFR display system with built-in data logging. Includes WEGO IV unit shown above, Bosch LSU4.2 5-wire wide-band oxygen sensor (two for dual channel system), sensor wire harness, 18x1.5mm weld nut(s) for mounting sensor on exhaust pipe, and software on CDROM   Versatile tuning aid for all carbureted and fuel injected engines displays AFR and logs over 2 hours data including AFR, engine RPM, and a spare 0-5V analog input for sensors such as throttle position or manifold pressure   Can be used for on-road or dyno testing  Suitable for automotive, motorcycle, and other small engine applications  Highly accurate with less than ±0.10 AFR error over 10.3 - 19.5 AFR range  Easy free-air calibration procedure corrects for sensor aging effects   0-5V analog AFR output (two outputs for dual channel unit) for interface to dyno instrumentation    Ultra-bright daylight readable blue LED display with automatic dimming under low light conditions  Wide supply voltage range from 11-16V allows operation from battery on small engines or race vehicles without an alternator. Current draw is approx. 1 amp (2 amps for dual channel unit)  Built-in USB interface