Each tank has a knurled non-vented cap, two 3/8" NPT female fittings on the top and one 3/4" NPT female fitting on the bottom, The tank measures 8" diameter in the middle, and 16" long end to end, With a 3-1/2 gallon capacity, it's perfect for non-highway carbureted builds, It's brushed aluminum finish allows you to install as-is, or paint or polish as desired, Mounting brackets are available separately which mount the tank on a flat suface, which also allows you to fabricate custom brackets if needed.