Developed over 30 years ago, PCI wiring is the standard in Off-Road communications. PCI helmets and headsets are compatible with what competitors call "off-road."IMSA and Peltor conductors look the same, but the pin configuration is different.Nascar looks different with a 3 pin conductor. We sell adapters to convert IMSA, Peltor and Nascar items to PCI here.For a better understanding of the pin configurations or to wire something on your own, click here for an explanation of conductor pin configurations.