Actual Dimensions: 20.75 x 20.75 x 4.38. Brand: Accumulair. 21x21x4.5 Ruud Protech 540018 style whole house air filters, exactly engineered to replace original manufacturer Ruud Protech 540018 filters. Completely box-formed - no assembly or combs required. MERV graded to ASHRAE 52.2 test grades ensuring particle capture as good or better than the name brand Ruud Protech 540018 air filter. Photo: Example filter picture as shown is not to scale and is shown for design purposes. Trade names and Ruud Protech 540018 part numbers are listed for air filter substitution 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).
Delivery normally takes another 1-3 days depending on location.
- 30-day 100% return policy.
Payment & Security
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