**Electret cotton** is a filtering material that uses permanent electrostatic charge to capture particles. Its core advantages are **extremely low airflow resistance** and **high dust-holding capacity**. It works like "electrostatic Velcro," efficiently trapping fine particles such as pollen, dust, and bacteria while maintaining good air permeability, saving energy and reducing noise. **Main applications include:** 1. **Automotive cabin air filters** — ensuring clean air without compromising AC performance. 2. **Medium-efficiency filters in residential/commercial ventilation systems** — balancing filtration and energy consumption. 3. **Low-to-medium protection masks** — filtering pollutants like smog while allowing easy breathing. 4. **Pre-filters in air purifiers** — extending the life of high-efficiency HEPA filters. It is ideal for applications sensitive to airflow resistance but should not be used in humid or oily environments.