ZIRCAR Refractory Sheet Type RSLE-57 is a low expansion, high-strength reinforced silica matrix composite designed for use as a high-strength insulator in induction hot press applications. RSLE-57 exhibits a very low coefficient of expansion (0.3 x 10-6 °C), which provides remarkable resistance to thermal shock up to 1200°C (2192°F) in an oxidizing atmosphere and permits its use with rapid variation in temperature in that zone. Beyond 1200°C, it transforms into a crystalline structure while maintaining its properties up to 1650°C (3002°F) providing that there is no significant fall in temperature. At temperatures above this, the material will exhibit surface glazing.