Single replacement HEPA filter.
HF-10 filter is also known as Eureka filter part:
The Eureka HF10 HEPA filter replacement fits Eureka 8800, 8850, and 8900 series upright vacuum models.
Some examples of upright Eureka vacuum cleaner models that use the Eureka HF-10 HEPA filter include include the following:
Eureka Boss Capture - 8830AZ
Eureka Capture - 8851AVZ, 8802AVZ, 8807AVZ, 8806BVZ
Eureka Capture + Pet Lover - 8852DVZ, 8853AVZ
Eureka FilterAir 8871AZ