Through the 3mm thin capillary hose the water is permanently transported in small drops to the plants. That ensures a constant equal rate of water in the soil, substrate or whatever you use. The end of the hose sticks next to the plant in the pricker - and you can watch the drops falling out.
It is a physical law - others would call ist physical mystery - however, anyway it's a fact, that the flow inside a capillary hose changes when you change its length. That means: you get twice as much water when you halven the length. So: Please NEVER shorten the capillary hose! Not even, if a shorter one would fit better ... it would confuse the entire irrigation.
Of course you find the prickers in this category as well.
To protect the capillary hose from choking by lime accumulation, you should pour Ata Clean into the water you're using.