Our Accumulair 21x21x4 air filter is solely engineered to be compatible with same sized 21x21x4 air filter type. Pleated electrostatically charged filter media traps airborne contaminants according to the MERV standard rating. Free of chemicals. Note: The example filter picture displayed is not to scale and is shown for style only. Catalog and 21x21x4 air filter variations are up to date as of 03/24/2020.
Shipping and Returns
- Our current lead times are 6-8 business days for standard filters (1"-6" thick sizes), and up to 10-14 business days for made-to-order filters (non-standard and 0.5" sizes). Delivery normally takes another 1-3 days depending on location.
- Shipping is FREE to the contiguous United States.
- 30-day 100% return policy.
Payment & Security
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