This green insert will come installed in your fittings. This insert is an adapter for 100psi pipe. If you are using 200 psi you will need to remove it. Make sure you put the white cuff back in before putting back together. Once you decide if you need the green insert and are ready to install, loosen the nut of you fitting and simply push your pipe all the way in and tighten the nut and your all set. Please make sure your pipe is cut off straight before putting together.