G4 filters are used in a variety of HEVAC applications where higher level air cleanliness is required over the standard pre filters. 

Our filters are manufactured with pleated synthetic media, and an expanded diamond grid with 97% open area. The casing is constructed from a heavy duty rigid water resistant card, with support members along the diagonals. The media is bonded to the support grid and the frame in order to avoid the possibility of air bypass. The case is designed for minimum resistance and maximum free area, the case is also crease formed to stop moisture ingress. Card construction with an optional metal frame for environments with high moisture content is available on request. The product can be manufactured in a variety of depths from 22mm to 97mm deep.