Stainless steel interior and exterior, aluminum back. Refrigeration system keeps food safe at temperatures between -8° and 0° Self-closing doors with 90° stay-open feature. Lock and keys included. Adjustable heavy-duty PVC coated shelves Pre-installed heavy-duty casters with brakes. Electronic control system makes it easy to adjust temperature set point and defrost frequency. Removable installation board makes it easy to access condenser coil for cleaning and service. HYDRO-CARBON R290 Refrigerant, which is environmentally friendly, and more efficient than R134a/R404a refrigerant.