Tesmotor Micro Drip Irrigation Tube, I.D 4mm/O.D 6mm Garde Watering Tube Line for DIY Automatic Irrigation System, Flexible Durable & UV-Proof Irrigation Pipe (20M)

Don't buy. I connected this tubing to standard drippers and to T connectors and the connections leaked, unlike when I use the more expensive 6mm tubing (a well known brand beginning with 'H') This stuff is black shiny plastic and doesn't fit tightly onto the connectors despite the internal diameter being similar to the more expensive tubing. I'll be using the well known branded tubing in future which feels more like rubber and which grips the connectors tightly.

This is 4mm bore tubing as described, but 6mm outside rather than 7mm. Micro irrigation systems are fairly low pressure so this shouldn't be an issue in general, however they can warm significantly and dilate if out in strong sun, potentially popping off from a barbed connector. Choosing watering times carefully is part of successful irrigation, and hopefully doing so would mitigate risks of failure, however whether this tubing will be more prone to problems remains to be seen. Used inside there should be less chance of a problem.

It was advertised as having a 7mm outer diameter but it was only 5.4mm. I have used this shiny thin walled black pipe before but it just doesn't last.

Not much to say here really. Outside diameter is described as 7mm but in reality, it is no more than 6mm, possibly a little less. It does not come with any drippers or connectors. I have used this sort of budget pipe in the past and it can work well if the fit is good. It has good memory and will grip connectors well. It is coiled up tidily with both ends accessible on the outside.