The second most popular filter material is silicone carbide, or SIC. It has a higher melting point than cordierite (2700°C+) however it is not as stable thermally, making packaging an issue. Small SIC cores are made of single pieces, while larger cores are made in segments, which are separated by a special cement so that heat expansion of the core will be taken up by the cement. SIC cores are usually more expensive than cordierite cores, however they are manufactured in similar sizes, and one can often be used to replace the other.