I bought this to replace my Eureka AirSpeed AS1000A bagless handheld vacuum. This is the filter on the back of the vacuum cleaner. It's really easy to swap out and essential to keep the air dust-free. The main reason I wanted to change my filters was because the vacuum was giving off a bad smell. I think the smell came mainly from another filter (original filter Eureka DCF-21 68931-1). I'm glad I replaced both filters, the AirSpeed is a great vacuum, but when those filters are dirty and not replaced regularly you can actually see a reduction in performance!