The Hoshizaki, 9534-40, Forty Pack Replacement E-10 Prefilters is perfect for food service applications and ice machines. This 6 gpm, 10 micron rated, is Works in single configuration water filter systems. Filters out larger dirt and rust particles. 
The EC110 Prefilter extends the life of the primary water filter cartridges.  Replace approximately every 15,000 gallons or 6-12 Months depending on usage and water condition. NSF Standard 42