GR120-1 is an 120mm plastic filter from U.S. Toyo Fan which comes in a 3 Piece Kit. Fan guard and media retainer is made of black molded plastic which meets UL 94V-0. Filter media is made of p olyurethane foam, 3.18 mm (0.125 in.) thick, 30 ppi. Filter media is washable and can be easily removed for cleaning or replacement Media retainer includes easy snap-on & off feature. Allows removal of media without removing fan mounting hardware.