The lid has a rubber gasket to keep dust and moisture out of the kit, allowing it to be ready at all times. You can stack stuff on top of it, and it can take a hit. There are many aftermarket kits for mounting ammo cans in different ways. There is no reason not to have this M240 kit in your truck all the times.
Please read the originial post here: https://www.webnetcreative.com/portable-12-volt-air-compressor-review/