7 layers and the 4" thick trailer wall

Let no other manufacture claim that their unit is better insulated, 7 layers and exactly 4" thick. It was fun drilling through this layer , it always comes out slightly off center, approx 1/8" no matter how hard you try the wood drill shifts a little.

This is the 4" vent for the 180,000 Btu water heater

Here the vent is closed to keep wind & rain out