How much does this cost to the nearest dollar?

Bibolic Replacement Humidifier Wicking Filter for Honeywell Humidifier, Replace 350 Series Humidifier Filter A (4 Pack)
Easy to Replace Just remove the old filter and install this brand new filter in its original position. The operation method is consistent with your original product. Adaptation Model Compatible with Honeywell series humidifier filter C work with HCM 350 series. Package Included 4 pack humidifier wicking replacement filters. After-sales Guarantee 3 months free replacement or refund for quality problems; if you have any questions, please contact us via email, we will serve you wholeheartedly. Fit for Honeywell HCM 350 Humidifiers. Include 4 Pack HAC 504 Replacement Humidifier Wick Filters. Widely Used Replacement Humidifier Filter

Price is $21.00
Price: $20.99