Aircraft Tool Supply Magneto Synchronizer (Single Deluxe)
Deluxe single-channel model with audible tone. Ideally suited for synchronizing single-mag engines such as ultralights, race cars, motorcycles, outboard motors, etc. Eliminates all guesswork and provides a greater safety factor by creating perfect timing quickly and reliably. Simply attach the two to the magneto and ground, then adjust until the "closed" LED goes out and the "open" LED lights up. An audible tone also sounds to confirm that you've hit the break point. Very easy to use and virtually foolproof.