For optimum performance replfilter every 2 to 3 months. Model # 4870 Series Features: Fits Eureka Ultra Smart Vac Models 4870A, 4870AV, 4870B, 4872B, 4874A, 4874B and 4875A. Genuine Eureka replacement 70082 motor filter. 1 motor filter per package. Item Dimensions: 6" L x 3" W x 0.5" H