Product review (5 stars): We use Sentinel filters for last two years. Replacing every 6 month. Happy.
All these filters are carbon blocks inside of a plastic container. The GE $40 filter set the price too high, and that drives prices up for a generic no-brand filters too. I believe even $20 price tag on that simple filter is too much. Anyway, you have to do it to remove chlorine from water. And if you try to save money, better get this less-expensive filter every 6 months, than keep using the original expensive GE filter for a year.