A flat plate evaporator can convert the box to a refrigerator or a freezer, determined by the temperature at which you set the thermostat (either a digital thermostat or a mechanical freezer or refrigerator thermostat).
The flat plate can be mounted on one wall or bent to conform to the shape of the box.

80F-Aluminum, Bendable – 13w x 9.5h #E50881
Price: $300.00
All Aluminum. bendable
24.75” wide x 8.25” high
Price: $259.00
All Aluminum. bendable
13.75” wide x 8.25” high
Price: $339.00

200F-Aluminum, Bendable – 40w x 10.5h
Price: $295.00
380F-Aluminum, Bendable – 37.5w x 14.5h
Price: $349.00

180F-SS-Aluminum with stainless steel cover, bendable – 22w x 12h
Price: $438.00
380F-SS-Aluminum with stainless steel cover, bendable – 40.25w x 16h
Price: $490.00