Trailer's got a Large Round plug. Your car's got a Flat socket. You're not rewiring anything at 7 am before a job site run. This Jaycar adaptor lead handles that exact mismatch: 7 Pin Large Round plug on the trailer side, 7 Pin Flat socket on the vehicle side. About 20 cm of cable between the two ends. Plug it in, test your lights and indicators, and you're on the road. No splicing, no calling a mate to see if he's got a spare lead. The full PA2061–PA2066 range covers every 7 Pin Flat / Large Round / Small Round pairing, so if this one isn't quite your setup, there's a sibling SKU that is. Match the plug end to your car's socket, the socket end to the trailer's plug. Sorted