What is it? Our flow restrictor is made of food grade material,which allows users to connect and disconnect quick and easy without the need of any other tools.It is used to give you the most RO water for the least amount of waste water production.It's purpose is to create back pressure on the drain line to help push water through the membrane but flow fast enough to keep it clean. Our flow restrictor fits standard tubing OD 1/4" Copper, CPVC, PEX and PVC tubing for most RO systems Where to use it? Applications include RO system, beverage dispensing, refrigerator ice maker, coffee machine etc. This quick connect fitting goes on the waste water line to help restrict the flow and keep your membrane clean. A flow restrictor to balance the brine solution coming off of the membrane and insurance to make sure there was enough back pressure against the RO membrane for proper filtration. you can also used to upgrade your system due to increase usage. This will take the headache out of an water filter installation How to use it? In the drain line that dumps waste water into the sink. So find the line hooked up to your sink drain and splice the flow restrictor in. There is an arrow on it to tell you what direction to connect it. To remove, just push in the outer circle on each end and pull right out. Just make sure your membrane flow rating matches this flow restrictor for best results. also You need to make sure the tubing is cut squared to insure no leaks. Be sure you cut the tubing even and straight, without crimping it. Then insert straight, and all the way into the connector. If it's crooked, or not inserted all the way, or crimped, it may leak What you will receive? Flow Restrictor x1