●Sub-frame structure, G3 White, G4 green and white; 
●Low initial resistance, large capacity of dust; 
●Can be cleaned, detachable, reused; 
●Cost-effective, economical and practical.
●Clean the system of clean room and air-conditioning of fresh air, pre-filtrate air, new vent, etc. 
●Central air-conditioning system primary filtration, air-conditioning purification equipment fresh air vent pre-filtration;
●Pre-filter of medium effect filter;
●Do the first level filtering in all filter systems.
●Filter Material: The initial effect of no gum filter cotton, the initial effect of spraying filter cotton, G3 White, G4 green and white;  
●Sub-frame: Galvanized folding frame, stainless steel folding frame, white paint folding frame;  
●Outer frame: Galvanized frame, aluminum frame, stainless steel frame; 
●Features: Stable structure, durable, removable structure can be used, the outer frame and the child can be reused. (Recommended repeat times in 3 times)