Today, we're going to be taking a look at the Atwood Amplock Trailer Coupler Lock. This is designed for the flat-lipped 2 and 5/16 inch coupler. The part number on it is AT89008. The Atwood Amplocks are designed to give you the maximum in security. This complete housing that you see here for our lock, it's made out of cast iron. This is going to resist any kind of freezing, shattering, burning, or… see more >