I ordered a set of RO replacement filters. One of them was the wrong kind -- the fittings didn't match up. Both the RO system's manufacturer and freshwatersystems.com's website image showed the correct filter. Their customer service solution is for me to buy (from them) adapters to make the filter work. Blame the customer for your screw-ups!
DO NOT DEAL WITH THIS OUTFIT! I made the mistake of following a link to their site from Amazon.com.