25 MICRON - The smaller the micron rating the better the entrapment capability 4.5 x 9.75 INCH - Universal Industry Standard Dimensions make these filters compatible with most 4.5” diameter drop-in whole house water filter housings Compatible with the following Aqua-Pure systems: AP801, AP801B, AP801-C, AP801T-C, and AP801-1.5-C WHOLE HOUSE FILTRATION - This filter cartridge fits into systems that filter water throughout the home for sinks, appliances, showers, laundry, dishwasher etc.. CHANGE FILTER EVERY 6 MONTHS - or sooner if a reduction in water flow occurs KleenWater KW811 dirt, rust and sediment water filter replacement cartridges compatible with A.O Smith AO-WH-PREL-R and Whirlpool WHKF-GD25BB. The rigid poly-spun construction effectively removes dirt and sediment with impressive flow rates of up to 20 gallons per minute. Each cartridge contains two distinct micron layers. Larger particles are trapped near the exterior and progressively finer particles towards the filter core. Thus the cartridge has exceptional solids-holding capacity and will perform longer. Please note this cartridge is equipped with the green end caps and gaskets to ensure a perfect fit. This replacement cartridge is an ideal choice for the value conscious consumer. The filter is constructed of NSF certified polypropylene material. Also included are 4 replacement o-rings compatible with A.O Smith model AO-WH-PREL, Whirlpool model WHKF-DWHBB, Pentair and GE filter housings. It is highly recommended to change the o-ring upon each filter cartridge change to avoid leaks and ensure the filter integrity. The KleenWater KW101 o-ring is constructed nitrile rubber which is dependable and has superior performance characteristics.