Aluminum Under Bed Cover Auxiliary Tanks.

Transfer Flow, Inc. - Aftermarket Fuel Tank Systems - 100 Gallon In-Bed Auxiliary Fuel Tank System - TRAX 4

Adding a 38 gallon Aux fuel tank under roll up bed cover : r/Duramax

ATTA 45 Gallon Diesel Auxiliary Below Bed Rail Tank AT45RBR — Elite Truck

Fuel Tanks Auxiliary Fuel Tanks by TFI - Quality Bumper

Combo Auxiliary Tank - BlackTread - Dee Zee

Transfer Flow Low Profile Under Tonneau Auxiliary Fuel Tank — Tank

ATTA 52 Gallon Auxiliary Diesel Tank and Toolbox Combo AT52TT-RT — Elite Truck

ATTA 45 Gallon Diesel Auxiliary Below Bed Rail Tank AT45RBR — Elite Truck

Adding a 38 gallon Aux fuel tank under roll up bed cover : r/Duramax