AXEON Capillary Flow Restrictors easily insert into 1/4" OD tubing located on the membrane waste line (aka concentrate, brine or rinse). The length of the flow control capillary line determines the flow restriction, shorter lengths allow more water to pass through at a greater rate of flow. Features: Compatible with all Quick-Connect and compression fittings Fits 1/4" OD tubing Delrin Material For Increased Strength Unique Design Prevents Clogging Easy Installation