Epdm pre-insulated stainless steel corrugated hose is made of durable stainless steel 304 /316 l flexible tube, with epdm insulation pipe, brass fitting, strong pe jacketing , flexible and easy to installation, it provides the maximum performance for all your solar thermal system. Specification: 1. Each coil includes both the feed and return pipes. 2. A flexible high-grade stainless steel tube 316l(or 304).Maximum pressure dn 16 /17.5 bar; dn 20/17.5 bar, dn25 17.5 bar rated burst pressure 200 bar 3. 100% genuine epdm insulation pipe. Light, flexible, closed cell, synthetic caoutchouc; free of pvc and non- cfc.Very good ozone resistance, uv-resistant. Work temperature range from -200 degrees to 150 degrees, max to 175 degrees