What is it? "Our Connector is suitable for use in hot(150°F Max) and cold (34°F Min.)water applications. It adopts Push-Fit technology, which allows users to connect and disconnect quick and easy without the need of any other tools.Operated by hand, it replace threaded or flanged connections, which require wrenches. It is used to branch off to different outlets for your RO unit.This Tee connector fits standard 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 is perfect for Tee in a water line going to your fridge or T off your water line under your sink for a filtration system as well as run two reverse osmosis faucets in back to back bathrooms from a single R/O unit. This will take the headache out of an under counter water filter installation How to use it? Just put in your 1/4" and 3/8" tubing into each end, pushing until it won't go in. To remove, just push in the outer circle on each end and pull right out. 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? 3/8" Tube OD x 3/8" NPT Thread Male Straight Connect x10