The SJO1Z system is used to discharge flue gas from high-temperature solid fuel (coal) boilers. It is resistant to the temperature of 600 degrees C. It is made of 1 mm thick sheet metal, grade 1.4521.

The elements of the system are connected to each other in a socket-like manner and there is no need to use gaskets. The advantage of using oval chimneys is the largest possible filling of the surface of the chimney shaft.