Holley EFI Gen 2 Dual Sync Distributors, features an improved shutter wheel, high-quality dual hall effect sensors, and an MSD cap and rotor. Designed to be used primarily in sequentially injected installations, can easily be used as a crank trigger for TBI system also. QPQ coated shutter wheel for superior corrosion resistance. These can be used with other EFI systems that support Hall Effect crank and cam sensor inputs.