Made primarily from cordierite (2MgO·2Al₂O₃·5SiO₂) and mullite, with a very low thermal expansion coefficient (2.0~4.0×10⁻⁶/℃) and excellent thermal shock resistance. Heat-resistant, non-stick, smooth and non-shedding, with low weight and energy consumption.

Suitable for firing lithium battery cathode materials, MLCCs and NTC thermistors where saggars must withstand rapid heating and cooling.