Generator Frame # Filter Kit # Replacement Filter Set # # of Filters Per Set Change Frequency Westinghouse(con't) 444 W 444 K W 444 S 4 cubes, 1 ring 6 months 444A W 444A K W 444A S 4 cubes, 1 ring 6 months 504A W 504A K W 504A S 4 cubes, 1 ring 6 months 587A/685A W 587A/685A K W 587A/685A S 4 cubes 6 months 2810A W 2810A K W 2810A S 4 cubes, 1 ring 6 months 3609 W 3609 K W 3609 S 4 cubes, 1 ring 6 months 3609.5 W 3609.5 K W 3609.5 S 4 cubes, 1 ring 6 months 3609.5A W 3609.5A K W 3609.5A S 4 cubes, 1 ring 6 months 5010A W 5010A K W 5010A S 4 cubes, 1 ring 6 months 5012A W 5012A K W 5012A S 4 cubes, 1 ring 6 months 5014A W 5014A K W 5014A S 4 cubes, 1 ring 6 months Westinghouse Exciters 256E W 256E K W 256E S 4 cubes, 1 ring 12 months 3609E W 3609E K W 3609E S 4 cubes, 1 ring 12 months Filter Replacement Pages: Air Filter Engineers, Inc. 2002