Polyurethane refrigeration (isothermal) doors are mainly used in refrigeration facilities and room refrigerators. It is distinguished by high thermal insulation and airtightness. Isothermal doors differ in their purpose, there are plus refrigerators and minus refrigerators. Plus unlike a refrigerator door, a freezer (minus) refrigerator door has a frame heating function that protects the door from ice accumulation. The refrigerator door can be with different openings: on the hinges or on the wheels.