One (1) stainless steel (for corrosion resistance),heating element for uniform generation of electric heat. Cabinet comes with a total of 1500 watts. 5" (127 mm) diameter plate castors – locks provided on front set. Equipped with one (1) factory installed interior kit option. Four (4) different interior kits available (see Kit Options). Entire cabinet structure and solid door are foamed-in-place using a high density, polyurethane insulation that has zero ozone depletion potential (ODP) and zero global warming potential (GWP).