Our Accumulair brand 11.5x21x4 air filter is specifically constructed to substitute for similarly sized 11.5x21x4 air filter specification. Pleated static charged filter media traps contaminants in the air relative to its MERV rating. Chemical free. Note: Sample filter picture shown is not the actual dimensions and is included to show style purposes only. Catalog and 11.5x21x4 air filter statements last verified on 03/24/2020.
Shipping and Returns
- Shipping is FREE to the contiguous United States.
- Our current lead times are 3-5 business days for stocked filters (standard 1"-5" thick sizes), up to 3 weeks for made-to-order filters (non-standard and 0.5" sizes).
Delivery normally takes another 1-3 days depending on location.
- 30-day 100% return policy.
Payment & Security
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.