1. **Metal Mesh**: Features a load-bearing metal winding mesh to ensure the filter paper is not affected by external forces.  
2. **Filter Paper**: Uses nanofiber filter paper technology, providing high air permeability while offering smaller pore sizes, lower resistance, higher filtration efficiency, greater dust-holding capacity, and stronger moisture resistance.  
3. **PU Adhesive**:  
   ① Made from high-quality polyurethane material, featuring polyurethane foaming with high flexibility and good rebound properties.  
   ② Uses a radial sealing design, allowing the filter element to automatically center, providing a larger contact surface for a leak-proof seal that effectively prevents dust.