Gray connector fits certain Ford TFI systems. We’ve confirmed this was used on certain 5.0 Mustangs among other applications. It also appears to fit some neutral safety switches and distributorless ignitions. Note that the gray color is not purely a cosmetic difference; this one is keyed differently from the black connector that we also sell. Note the notch on the left side of this connector; on the black version, it’s on the right instead.