MSD 6EFI universal ignition control box part # 6415 is specifically designed to work in harmony with a variety of electronic fuel injection systems such as MSD’s Atomic EFI or Holley’s Sniper EFI. it delivers better throttle response, smoother idle, quicker starts, and maximum power throughout the entire RPM range. This reliable capacitive-discharge ignition fires a series of multiple sparks that last for 20 degrees of crankshaft rotation at lower rpm. A rev limiter protects the engine in the event of a missed shift or driveline failure and is easily adjusted with rotary dials in 100-rpm increments. MSD 6EFI Universal Ignition Control Boxes are compatible with 4, 6 and 8 cylinder engines with magnetic-pickup, electronic, and even points distributors and come complete with detailed wiring instructions for a hassle-free installation.