SKU 55821-13 replaces 55821-063M HF8-S, 55821-13, is a replacement cartridge for the commercial water filter systems. 3M HF8-S reduces scaling. 3M HF8-S Features Sanitary Quick Change (SQC) system - requires no contact with the filter media during change-out Does not require any pre-installation 6.0 GPM flow rate 70,000 gallon capacity NSF 42 certified and follows the highest benchmarks for water filter cartridges