Puretec PX052 Compatible Sediment Filter, for WH2200, 20″ x 2.5″

Polyspun Sediment Filter Cartridge
Highly effective at trapping Sediment, Dirt, Sand, Silt, Loam, Clay, and Rust.
Replacement frequency depends on water quality and usage. However, sediment filters should be replaced at least every year.
NSF Certified Sediment Filters.
Triple Gradient for higher capacity. 
1 micron filtration: It can capture particles bigger than 1-micron.