MICROLINE R.O. Split Pre & Post Filter SET Set Includes:1). Split Sediment/Carbon Post Filter - # S70281). Granular Activated Carbon Post Filter - #S7025 1st Stage Pre Filter for Microline TFC R.O. Systems on city / chlorinated water. Original Microline Split Carbon Block / Sediment Pre Filter # S7028 for use in all Microline TFC Reverse Osmosis Drinking Water Systems : TFC 300, TFC-335, TFC-35A3rd Stage Activated Carbon Post filter for all Microline R.O. Systems. Microline Activated Carbon Post Filter # S7025 is used for a polishing filter to improve the overall taste of the product water. Fits Microline R.O. Systems : TFC 300, TFC-335, TFC-35A