The discrepancy you’re experiencing suggests that the wrong tank or an incorrect label was shipped. To resolve this, please check the tank for any model number or SKU markings, typically a raised plastic area, to confirm the exact product you received. Providing photos of both the tank and the label will help us verify your order and expedite sending you the correct 70 gallon fresh water tank (SKU 4364), which measures 77 5/8" long, 20" wide, and 11" tall. Once we confirm the details, we will arrange a replacement shipment promptly to ensure you get the proper OEM RV water tank designed for your needs.