Clack Corporation manufactures the Microline reverse osmosis systems which have been time-proven to be solid and dependable reverse osmosis systems.  The product is not always called "Microline" as it has been "private-labeled" by many other companies under their own brand name.  The system comes in two (2) configurations:  the 3-stage model (on the left) and the 4-stage model (on the right) , which includes an additional "in-line polishing filter."