If you're upgrading to Holley EFI and currently have an MSD four-magnet crank trigger, this is your sensor!
Designed as a drop-in sensor replacement for flying magnet crank trigger setups using a 3/4-16" threaded magnetic sensor. This sensor is a Hall Effect sensor, meaning it outputs a square wave signal, which is ideal for use with most Electronic Fuel Injection Systems. This sensor is to only be used with a trigger wheel with "flying magnets". It does not detect a ferrous steel target.