Vertex Water Products, of Ontario, Calif., adds to its line of undersink RO water filters with the model 3C-4.1. This 4-stage RO water filter has the features customers want—plenty of clean water provided by the 75 gallon per day membrane, and fast water flow at the faucet with 3/8″ tank-to-faucet tubing. Dealers will like the ease and speed of filter replacement with the use of three standard cartridge filters including coconut shell post filter plus the NSF-approved quick connect fittings.