The rectangle double wall Refueling Transfer Tank is the most heavy duty tanks we have in our lineup. Our standard fuel tanks range from 38 to 110 gallons. The Two- 2" bungs allow for reversing the fuel fill cap and fuel transfer pump to the side you prefer best. The rectangle fuel tank is also the ideal shape if you require a double wall refueling transfer tank for you specific application. If you want to keep most of your bed space check out our more slender aluminium fuel tank designs, some only require 9".