- Using double skin coated craft to stick the PVC fabric with high temperature. - high tensile, shockproof, water proof feature 1. Made of strong biaxial polyester. 2. Using double skin coated craft to stick the PVC fabric with high temperature. 3. High tensile, shockproof, water proof, acid and alkali-resistant, and structure-stability. 4. Each single duct is connected by spigot joint, it is ...