Electronic Specialties 125 Digital Tach/Advance Timing Light - Professional Timing Light with High Visibility LED display Measures ignition spark advance from 0-90 degrees 2 & 4 Stroke Tachometer measures engine speed up to 9,999 RPM Brilliant Xenon flash at all speeds Detachable & replaceable cable set Designed for precise tuning and diagnostic work Accurate up to 9,000 RPM Works with 12 Volt electrical systems