MICROLINE R.O. Split Pre / Post / Inline Filter Set Set Includes: 1). Split Sediment/Carbon Post Filter - # S7028 1). Granular Activated Carbon Post Filter - #S7025 1). 6" Inline Chlorine Taste & Odor Filter with 3/8" Quick Connect Fittings 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-35A 3rd 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 4th Stage is the Activated Carbon Filter. This is a bullet style filter, and is used as the Post Filter or Polishing Filter. This filter utilizes 3/8" quick connect fittings on the inlet / outlet for easy removal and installation. Older S