A pack contains 2 filters. Life expectancy of the filter: 12 months. Compatible with the Honeywell HPA100WE air purifier. Captures up to 99.97% of airborne particles at 0.3 microns. Golden standard for people with allergies, hay fever, asthma. Helps you breathe with confidence. HEPA filter technology. Size H26.2, W17, D8.4cm.