Culligan FM-5R Level 3 Faucet Filter Replacement Cartridge

The filters do their main job very well -one piece of evidence being how much less scaling there is on humidifiers etc. that I regularly fill with filtered water now. And although there is some inevitable slowing of the flow rate as the filter gets used, it doesn''t get unusably slow as some other filters do. I rely on the metering feature to tell me when the filter is used up.

Speaking of which, the meter is pretty good, but it can get fiddly. You''re talking about an assembly of molded plastic parts, so the occasional less-tight-fitting cartridge will occur. Right now I''m dealing with one where the cap, which holds the electronics, tends to pop off, sometimes bending the delicate contacts on the cartridge in the process. They can of course be easily straightened back out (without tools), and the cap reattached, but if you''re averse to doing such things (or physically unable to do them), the metering type of filter system isn''t for you.