I created this guide to prevent the canula tube from bending, it fits multiple types of canula. This really helps in the soft tube not collapsing and reducing airflow (especially on warm days). this is particularly helpful on warm days. . To assemble, press the 5 pins in one side, lay the canula in the guide. Press on the other half, I use pliers for a snug fit. No glue needed. Be careful not to pinch the tube. There is sufficient flex a the bottom to slide the canula base over the nipple.