I bought this specific cabinet for my boiler for 85 euros. It is without insulation and its quality is relatively good. Insulated boxes cost almost twice as much money. So I gave another 7 euros or so and bought 2 sheets of plywood, 1.20x0.60 and with a thickness of 2cm, and glued them inside the box! The box is now skyrocketed! The insulation is perfect! Now, the chimney can come out from the side (it has notches) right - left, but also from above. It took me more time to remove the glued plastic film from the metal sheets than to assemble it!