$25 off orders over $75 + free shipping with rebate. Promo code: FLINGAdditional Organic Enzyme Refill for the Odor Reducing Air Purifier. This is the revolutionary enzyme that helps the Odor Reducing Air Purifier destroy pollution. Refills have a 1-year life span. Add this Organic Enzyme to your Odor Reducing Air Purifier each month for maximum performance. Bottle is 6 fl. Oz.