Auxillary Fuel Tank

Tank is from KSK marine in Lake Havesu, also RDS makes one for gasoline. As far as the cap, I believe it is vented but short not like the ones we have on our vehicles. The gas is run through a pump and I have to use a switch to fill, it does not gravity feed. And, as far as running down the road for 50o or 600 miles before stopping, that don't happen either. we use it as additional fuel, if running low while driving I can flip a switch and keep on keeping on, but still stop at least every 2 hours max and get out and do the stretchy thing and usually bathroom stop or whatever. So thanks for the info, I will check on the cap thing as well. Good Luck& Be Safe ! ! !