They seem to be highly unreliable in providing a steady drip. Off to get a load of end-drippers to replace them. Am I the only one to have these problems?
Found a website for the supplier "www.sherwoodagencies.com". T'Internet reports that it has gone bust. Can't say that I am surprised.
I tend to use end of line drippers but both need a constant water pressure to give a steady drip rate. Also they will probably be affected by temperature especially if in a greenhouse.