Compatible with the Oreck® Air Response Turbo Model # WK18500 Only Oreck® Certified Filters should be used with Oreck® air purifiers to ensure optimal filtration & performance. Damage to the product caused by the installation or use of non-Oreck® Certified Filters or components shall not be covered under and is excluded from the warranty. Compatible with the Oreck® Air Response Turbo Model # WK18500. Includes (1) 3- Stage Replacement Filter which provides up to 12 months of protection*.