Green Klean Replacement Micro Hygiene Filter for All Windsor Sensor upright vacuums (OEM# 5301ER, 8.600-522) 25 Filters, GK-5301ER GK-5301ER Green Klean® Replacement vacuum filters use the highest quality filter media. Designed specifically for commercial use, they are always equal to, or exceed OEM quality. Better filtration means cleaner air, less dusting, and longer secondary filter life. Each bag is printed to easily identify the vacuum it fits. Clean with Confidence, Replace with Green Klean.