Check the listing for details. Martech 88890 Filter Pkg - Model 80- 6 Month Service Kit. Condition: New. Listed at 335.68 USD. Kit contains: (1) - Stage One filter (1) - Stage Two filters (2) - Stage Three filters (2) - Stage Four filters NOTE: This kit will maintain your system properly for 6 months Each product has a suggested filter change out schedule that is outlined in the owner’s manual. Failure to change filters as necessary, may result in permanent damage to the product, but more importantly can cause serious illness or injury to the user of the product. In order to properly maintain your Martech Services Company products, it is imperative that you replace the filters, on a regular basis.Always change filters as per manufactures recommendations. Expedited shipping available at checkout Add item(s) to cart and enter your shipping information for quote