This is the Spin Secure locking fuel cap that is used on the ATI refueling/transfer tanks. Comes with the cap and key.
50 Gallon Fuel Tanks for Truck Bed — Tank Retailer
Suitable for use on below ground and above ground oil heating storage tanks. Also for use on refrigerated trailer (reefer) tanks. Made from heavy duty
Heating Oil Tank and Reefer Fuel Tank Locking Cap | For Transfer Tanks & Above Ground Commercial Tanks | Prevents Theft & Fuel Vandalism | FSS 750
ATI 55 Gallon Rectangle Refueling Tank
Fuel Tank Accessories Locking 2 1/4 Diesel Fuel Cap for Reefer/International MD Semi Trucks : Automotive
RDS 60 Gallon Transfer Tank & Toolbox Combo Black Aluminum 55X20X19.5 — Elite Truck
ATI 65 Gallon Fuel Safe Refueling Tank & Toolbox Combo
ATI 38 Gallon Rectangle Refueling Tank
ATI Spin Secure Locking Cap (For Refueling/Transfer Fuel Tanks)
Aluminum Tank Industries
Transfer Flow 50 Gallon Fuel Transfer Tank System Diesel or Gasoline - — Elite Truck
Spin Secure Locking Fuel Cap - Transfer Flow Tank Tips
Spinsecure Versalock Series 2 in. Vented Locking Cap for Transfer, Auxiliary and Reefer Fuel Tanks FSS-754 - The Home Depot