The case is made using moulding plastic obtained with 75% of recycled plastic and 25% of virgin material. It has also been constructed with steel, aluminium, wood, or cardboard. The interior walls are made with aluminium, actually used printing photolithograph sheets. Whereas the bottom is painted black to increase absorption of the radiation, the rest is left without treatment to reflect it against the cooking pot. The insulation is achieved with glassfiber and high density glassfiber in the bottom. Other possibilities include materials such as cotton, wood, rockwool, jute, hemp, etc, always considering that the lower aluminum side, where the pot will be placed, needs to be resistant and maintain the insulation thickness, despite the pots weight. The transparent window is a resistant acry