The Kilo has many different versions. The flue can be supplied attached to the top. The Kilo can be supplied as a rotatable and a static stove. This can be changed at a later date, even if the Kilo has seen some service. Combustion air can be supplied through the floor, the wall or just from the space where the Kilo stands. Yes, that too can be changed at a later date. The Kilo is available in black, anthracite or untreated. Both the steel and the side stones. No, that cannot be changed at a later date.