Mammoth Choppers has teamed up with Drucci Steel to produce a new line of custom oil tanks. The Double Trouble oil tank features 2 spherical mild steel balls that are perfectly tig welded together in the center. 1/8” wall thickness. The 3.5 quart capacity is perfect for your custom Bobber or Chopper project. ¼” NPT fill bung and 2 -¼” NPT drain bungs located on the bottom of the sphere. Also included is a knurled/vented cap. Made in the USA.