CFS Reverse Osmosis (RO) 10" Replacement Filter Kit (Sediment, Carbon) Kit Includes: (1) 1-Micron dual density gradient sediment filter, (1) 1-Micron Carbon Block Pre-Filter. Features: 1-Micron dual density gradient sediment filter is highly recommended due to longer life and cost effectiveness. Precision manufactured from 100% pure Polypropylene fibers. The fibers have been carefully spun together to form a true gradient density from outer to inner surfaces. 9-7/8" standard size cartridge is self-sealing for a tight fit in RO units.1/2-Micron carbon block pre-filter is a high-quality replacement for your existing carbon filter and works best with our 1-Micron dual density gradient sediment filter. 9-3/4" Standard size cartridge includes rubber gaskets at both ends to ensure 100% water flow-through. These replacement cartridges are interchangeable with Coralife, Kent Marine, Seachem, Spectrapure, and all other RO or RO/DI units that use standard 10" cartridges.