Actual dimensions are 20.75 x 20.75 x 4.38. Accumulair brand, 21x21x4.5 Rheem Protech 540018 style whole house air filters, exactly constructed to be an alternative to the name brand Rheem Protech 540018 filters. Fully box-formed so no forming or combs required. MERV classified to ASHRAE grades establishing particle capture to the level of the original manufacturer Rheem Protech 540018 air filters. Photo: The example filter image as displayed is not the actual dimensions and is displayed for style purposes only. Brand names and Rheem Protech 540018 part numbers used for filter substitution identification purposes only.
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), and up to 8 weeks for bag filters.
Delivery normally takes another few 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.