Insert the end with the PEX about the end of the fitting. Slide the top in the PEX tubing that has the crimp ring or cinch clamp on it around the end of your fitting that you choose to screwed onto the copper tubing. Force it on so far as https://angle-stop-vavle89765.blogsmine.com/30939326/the-fact-about-1-2-copper-street-90-that-no-one-is-suggesting