Review on ADSDIA Aluminum Charger Waterproof Motorcycle by Mike Wachtel

Works great so far. I have a 12V outlet on my boat but I need a direct USB connection so I don't need an adapter. Easy to connect, red to hot, black to ground. The hole diameter is 1 1/8 inch (1.125 inch). I used a 1 1/8" hole saw to install it into the boat console. The console box was made with a 1/2" layer on the starboard side and a 1/4" layer on top. As thick as can be You only drill with a hole saw. Assembly was easy, just tighten the nut at the back. Very clean device.