Premium ceramic water filter cartridge compatible with Zen, Max Water purification system or any other coolers and household buckets.. Compared to the original part CR-F. The dome filter has holes size from 0.2 to 0.5 micron in diameter. These holes will trap dirt, debris from water. Maintenance on the dome filter once a month is highly recommended to extend the life span of the filter. Simply scrub the dome surface under cool running water will unclog the pores on the ceramic and expose a new layer for use. The ceramic filter is suggested to be replaced after 1,000 gallons or 1 year, whichever comes first. Dimension: 4" x 4" x 4.4". 1 filter included.