Fine Mesh: The mesh and grid spacing of this tent vent cover is small enough to block most particulate matter and small pollutants Material: The pipe filter cover is made of waterproof and reusable Oxford cloth It does not affect ventilation or enter the internal environment, thus protecting the plants and keeping them in good condition Easy to use and clean: Simply place the particle filter cover over the vent and secure with the drawstring and So it is easy to replace, hand washable or machine washable, Manufacturer: Ounfhtrttk