RFS13 Fits Sunbeam model 2587 and 2588. Measures approximately 8 3/4 x 11 x 1 1/8. Effectively collects airborne particles&#44; pollen&#44; mold and spores&#44; pet dander and hair&#44; For optimum performance&#44; change your filter once every 6 months or sooner&#44; depending on the air