The Filtrex FXHTC11CL2 is the correct replacement filter for the following reverse osmosis systems: Clark RO systems that accept 11.6" L x 2" W carbon pre-filters Hydrotech RO systems that accept 11.6" L x 2" W carbon pre-filters This Filtrex FXHTC11CL2 Water Filter is a 11.60" inch reverse osmosis prefilter cartridge used for the reduction of the bad taste and odor of chlorine as well as dirt, sediment, rust, sand, silt, and other impurities down to the 10 micron level. This Hydrotech RO pre-filter is compatible for use in all Hydrotech reverse osmosis systems and Clack reverse osmosis systems which use 11.60" length x 2" width carbon prefilters. The Filtrex FXHTC11CL2 is one of many eco friendly filters from the CL2 Series of GreenBlock filters from Filtrex - these high performance coconut shell carbon block water filter cartridges are manufactured using a unique process that reduces harmful green house gas emissions. This Filtrex carbon block filter cartridge is made from high performance coconut shell activated carbon which features a unique carbon binder system plus more micro pores compared to other types of carbon filters. Filtrex carbon filters have a very low pressure drop, high dirt holding capacity, and advanced contaminant reduction due to more carbon surface area in the filter. No carbon fines are released during filtration. FXCL2 filters can be used as a prefilter for a wide range of reverse osmosis systems which are compatible with a 11.6" length X 2" width carbon filter cartridge. With durable polypropylene end caps and inner/outer wrapping along with a polyethylene netting, these filters are designed to last. Filtrex FXHTC11CL2 Hydrotech/Clack Carbon Water RO Prefilter Specifications: Pressure: 1.6 PSI Micron Rating: 5 microns Temperature Range: 40 - 180 F Filter Media: Coconut shell carbon block Exact Dimensions: 11 3/4" length x 1.9" width Filter Life: About 3-6 months depending on frequency of use Flow Rate: About 1 GPM @ 1.6 PSI (may vary depending on specific RO system) This Hydrotech filter is NSF Certified to Standard 42 for Material Safety and is also manufactured from NSF Standard 61 Certified coconut shell carbon. Additionally, it is NSF / WQA Gold Seal Listed.