Brake switch jumper wire, 4 inch long extension. Bridges the under dash wiring harness and the brake light switch. Not used on many cars, we suspect that it was used on the assembly line when the brake switch plug didn't reach the brake switch. Adding one of these jumpers, saved time from re-routing the under dash wiring harness.
Ford master part numbers: C5AZ-14489-C, C8ZA-13K408-A and C8ZZ-13K408-A