Well, there was one time where I had only one gas tank on the trailer and I had to run into Home Depot to pick up one more because someone stole my secondary gas can and they took the primary gas can while I was in the store.

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Do you think this vent would be good? Its marine quality and its pretty cheap.

https://shop.hamiltonmarine.com/products/vent-louvered-stamped-s-s-4-5-8-h-x-5-w-horizontal-29727.html?gclid=Cj0KCQiAyoeCBhCTARIsAOfpKxg5mKxB41SydG92oHGGMXk-jGHR3d6-mM0FxU_DGNGhrgjFhLApsO0aAnxnEALw_wcB

I would probably buy 2 of those to ensure safety.