●G3 White, G4 light green;
●Low initial resistance; 
●Can be cleaned, detachable, reused; 
●Economical and practical.
●Clean the system of clean room and air-conditioning of fresh air, pre-adsorb air, etc. 
●Central air-conditioning system primary filtration, air-conditioning purification equipment fresh air mouth pre-filtration;
●Pre-filter of medium effect filter; 
●Do the second level filtering in all filter systems.
●Filter Material: The initial effect of no glue filter cotton, the initial effect of spray filter cotton, paint fog felt, top cotton, glass fiber filter cotton;  
●Support Net: Galvanized NET, aluminum NET, stainless steel net, white paint net;  
●Outer frame: Galvanized frame, aluminum frame, stainless steel frame; 
●Features: Filter can be reused after cleaning, removable structure can be used, the outer frame and mesh can be reused. (Recommended repeat number 3 times)