Whole House Sediment Water Filter, Multi Gradient Density 25/10/5/1 micron, 20-Inch x 4.5-Inch. Fits Home Master Water Filter systems, and 20-Inch Big Blue filter housing. 25-micron outer layer; 10-micron layer; 5-micron layer; 1-micron inner core sediment water filter. Reduces turbidity, dirt, sand, silt, and rust particles down to 1-micron. Nominal four separate filtration layers provide triple the dirt-holding capacity of similar sized filters. Designed for high flow rate with low pressure drop; and chemical and bacteria resistance. Dimensions: 20-Inch x 4.5-Inch; 1-Inch center hole. In the box: replacement filter cartridge.