The Yeti Cooler has a permanent Preserve spell effect on it at all times. The amount of capacity as well as its opening size varies based upon its rarity.

Rarity                  Capacity                         Opening

Common            10lbs.                              1ft. x 1ft.

Uncommon        50lbs.                              1.5ft. x 3ft.

Rare                     500lbs.                            3ft. x 6ft.

Very Rare            5,000lbs.                         10ft. x 10ft.