SST-Porous® Alloy& Screw In Protective Vents, research & developed by SST independently，made from SST-Porous® PTFE (No woven with polyester support) and compelted lower cover alloy parts（alluminium), combined together by mechanical bonding. then put alloy Upper Cover. The alloy upper cover could protect PTFE porous membrane material, prevent it from puncturing, collision and other damages and so improve the vents's service life, safety and reliability and durability. The robust entire components results in new functionality and characteristics, reducing costs, and enables one-click installation.