Deal of the Day: 1/25/12 RO/DI Replacement Filter Kit Regularly $49.99, Today only $39.99 (Expires at midnight!) PRODUCT DETAILS 1 micron dual density gradient sediment filter is highly recommended due to longer life and cost effectiveness. Manufactured from 100% pure polypropylene fibers. The fibers have been carefully spun together to form a true gradient density from outer to inner surfaces. 1/2 micron carbon block prefilter is highly recommended to replace your existing carbon filter and works best with 1 micron dual density gradient filter. Color Indicating Mixed Bed DI Cartridge is the most effective and easy to use DI cartridge available. It’s unique color changing ability takes the guess work out of determining when it is exhausted. PRODUCT REVIEW by Jeffrey Fuller from Gallatin, TN "The replacement filters are of first-rate quality. They were a perfect fit for my Kent RO/DI. Pay attention when installing the mixed bed DI cartridge, the top is not labeled and the cartridge must be installed right side up. If you don't you will not receive RO water from your membrane. Make sure the closed cap end is placed in the bottom of the canister. This product is well worth it, best PSI ever from my unit."