This 5mm (1/4inch) black micro irrigation tube is mostly used to connect drippers for pots and baskets to the main 13mm (1/2inch) line.

How to fit 5mm Polytube to the 13mm tube:-

1. Pierce a hole in the side of the 13mm tube near the pot or plant, using the Garden Magic Hole punch (this comes with 20 plugs to plug unwanted holes).
2. Insert a 5mm Barbed Joiner.  This is a double ended straight connector with a small flange in the middle to stop you pushing it in too far.
3. Then push the 5mm tube over the free end of this connector - and your connection is made !

Then fit a dripper (Econo or adjustable) and arrange it over your plants in the pot or basket.