Replacement filter cartridge for iSonic pump station used in conjunction with iSonic ultrasonic vinyl record cleaners CS6.1-PRO, CS6.2-PRO, P4875II+MVR10-PRO, P4875-NH+MVR10-PRO. The pump station drains water out and pumps it back with a flick of a switch. 100% of water goes through the filter when it's being pumped back. It has 10-micron pore size and lasts about 500 to 1000 albums.