Luna CPAP/APAP Replacement Filter (2-pack) 3B Medical Sale! from $ 4.95 Qty. Add to Cart This item is currently on backorder but you can still purchase it now and we'll ship as soon as more become available. If you are interested in a quote for expedited shipping, contact us at 844-757-9355 or email us at firstname.lastname@example.org Replace every 3-6 months per manufacturer's recommendations. This is a pack of 2 filters.