BTTRZ is a flexible mineral-insulated fire-resistant cable: stranded copper conductors wrapped in mica tape and inorganic compounds, sheathed in a corrugated copper jacket. Rated 0.6/1 kV, 4×16 mm². Non-combustible and free of halogen or toxic smoke when burning, it keeps supplying power under a 950 °C flame, suiting fire lifts, emergency lighting, exhaust fans and fire pumps in high-rise buildings, subways and tunnels.