Fantastic for the price. You can't go wrong with these.
Perfectly good quality and do what they're supposed to. I use about 10 of these cables (although half are the longer 3m ones, but same quality) on my setup and have never had any problem. Some are direct from controller to instrument, others are used on MIDI Thru boxes and/or with MIDI extension cables, and all work perfectly.
I had previously bought some cheap MIDI cables from elsewhere online (I won't say where but you can probably guess) and while they 'appeared' to be of reasonable and similar quality, I found that some instruments/synths' notes would get doubled or missed etc. Some very strange behaviour I'd never have thought could be down to the cable, but as soon as I swapped them out for Thomann's ones, I've not had a single issue.