WORK WITH THE BARBER COLMAN DYNA CONTROLS I SELL VARIABLE RELUCTANCE GEAR Tooth Speed Sensor 5/8" diameter Electrical magnetic speed sensor unit originally sold through Onan probably for use with a governor control unit. NEW OLD STOCK NOS means new old stock. These are items that are still in new and unused condition that have been on the shelf or in storage for a number of years. Most of my items are in the original factory boxes or cases. Some of these boxes show a good bit of wear and tear from storage time and handling. Please send part numbers when inquiring about certain parts. Sincerely, Mike MESSAGE FROM A CUSTOMER : Hi Mike, I was able to get the sensor to work with my system and find a scope to measure the output. I measured it at 5V peak-to-peak. Thanks again. Joel