The battery box is sized to fit the standard Odyssey 625 battery. Like others, I added piano hinges to make access easier. It will have a thin layer of foam on the inside, so I opted to rivet the hinges from the outside. The bottom piano hinge has a tab where I'll add safety wire for the pin.I decided to add a reinforcement doubler on the inside. The battery is heavy and the firewall really flexes under the weight. It's probably unnecessary.