The straight stop valve is used where the water pipe enters the room to allow for easy shut-off of water flow to the end fixture allowing for maintenance and repair without having to turn water off to the entire home. Can be connected to PEX pipe using copper crimp rings or stainless steel clamps. The 1/4 In. compression outlet with the supplied ferrule and compression nut, can be used with 1/4 In. OD pipe or 1/4 In. supply line.