I am looking at putting in some piping in greenhouse : 13mmm and 4mm drippers
etc.

I see that regarding putting 4mm spurs off 13mm pipes there seems to be two
ways of doing it. Expensive connectors: Gardena reducing joints or the little
plugs which plug in to a hole you make in the wall of 13mm and spur off the
4mm.

I notice that there are two different sorts of those : one has barbs on both
ends, the other has barbs on one end and is threaded at the other.

So - any preferences - and what are the differences between the
barbed/threaded 4mm spurs off?


Regards.