Fitment: Transfer tank vented cap replace for Dee Zee Fill-Rite transfer tank cap and fit for standard 2" NPT threaded tank bung base. Diesel tank cap works well for ground, farm, commercial and distillate tanks, such as transfer tank, fuel tank, gas tank, diesel tank, auxiliary fuel tank, mobile fuel tank and weather guard tank.

Both Directions Vent: When loosing the diesel tank cap, the venting pressure tank cap vent pressure inside the fuel tank to outside and release dangerous vapor build up to prevent over-expansion of the diesel fuel tank. And vented fuel cap allow air into the diesel transfer tank to prevent vacuum forming and collapse the tank when you draw out fuel.

Added Security for Diesel Tanks Fuel: Lockable diesel fuel tank cap fit for 1/4" - 5/16" diameter shackle padlock (not included), which secure your fuel tanks and prevent costly oil fuel from theft,tampering, siphoning and vandalism. Just put a padlock in lock hole that is right on one of the tabs on the base and the tabs will hold the lock.

Prevent Leaking: Transfer tank fuel cap with spring loading and inside gasket is seal when tightly closing to prevent leaking and excess gas vapor venting even drive in road.

Easy to Use: Align the vented gas cap with the notch, push down and clockwise twisting to tighten the diesel tank cap all the way. To remove transfer tank cap, counter-clockwise twist slowly to the notch to vent pressure. Push down and twist to lift pressure vent fuel cap and remove.

Heavy-duty Transfer Fuel Tank Cap: Made of high quality materials featuring waterproof and corrosion resistance to long term serve your diesel tank. The whole tank pressure fill cap includes a removable transfer tank vented gas cap and2 inch heavy-duty cast iron base.