Punch a hole in your 1/2" or larger mainline tubing with one of our punches specially designed to ensure an accurate size hole. Insert one end of the 1/4" barbed fitting into the end of the 1/4" micro tubing and once complete, insert the other barbed end of the fitting into the punched hole in the 1/2" mainline tubing. When you hear the 'snap' you are done. Please refer to the video found at this link