The Multi-Layer Composite Anti-Smog Screen Mesh is a 3-layer functional window screen for high-pollution environments. The outer PET 20-mesh layer blocks insects and coarse dust, the middle high-density non-woven layer efficiently filters PM2.5, pollen and vehicle exhaust particles, while the inner 60-mesh polyester layer provides light reflection and shading with good airflow. With durable PET and polyester construction, it offers long-term outdoor weather resistance, ideal for residential windows, offices, schools and hospitals requiring cleaner indoor air.