The Eureka 110375 Filter is a single 12.5 inch blue inverted filter bag that is a replacement for several Eureka and Electrolux central vacuum units. It is a permanent, drop down, self-cleaning filter bag. When vacuuming, the bag with the weight inside it is sucked into the central vacuum unit's main canister. When the power is turned off, the filter falls and shakes off the debris into the dirt can.