● For 20cm and 25cm blade diameters ● Cap-type filter for easy installation, just put it on ● Usable with ventilation fans from all manufacturers with 20-25cm blade diameters ● Lightweight and durable pyramid-structured cap-type filter with a frame to prevent entanglement ● The frame can also be used with replacement filters for other companies' covered ventilation fans ● Material: Flame-retardant non-woven fabric (recycled PET used)