these filters the RF20 are considered by far more expensive than many other R/O systems, and last less time. Brondell should stop this outrageous prices, specifically because the delivery of water is very slow. The only advantage is the bayonet connection which make it easy to install/uninstall the cartridges. If price does not go down to 45 dollars I will abandon all together the brondell RO system and recommend all my friends to do the same. Some are with the same opinion as mine, you are way too EXPENSIVE