These are 4 litres per hour constant flow drippers.  They are connected to each other with 5mm Polytube, each dripper being placed close to a plant or where irrigation is desired.  End the line with a button dripper.

Often supplied from a 13mm Polytube main line.  Connect the 5mm Polytube to the larger 13mm Polytube with a 5mm barbed joiner, take the tube to the first plant, cut the 5mm tube and and insert a dripper.  Connect the coil of 5mm tube to the other end of the "tee" of the dripper and continue to the next plant. 

The dripper has an outlet to which you can connect 5mm tube - for example if the main run of 5mm tube is at ground level but you want to run up the side of a pot.  Use a pot stake to secure the tube in place in the pot.  So you can either allow the dripper to drip directly by the plant, or attach 5mm tube to lead the drip to the plant.