This T-adapter with a shut-off valve allows for quick add-on connection for under counter water filters. Inserts between existing brass/chrome cold water supply valve and braided water supply line going to faucet. 3/8” female compression fitting x 3/8” male compression fitting x 3/8” quick connect for tubing going to filtration system. Includes shut off valve. This T-valve adapter is made from tough Polypropylene plastic. Approved for water filtration systems.