Quite a good tuner. It lights up on its own when you attach it to the headstock. The elastic on the clip needs attention because it easily comes off.

I had one which the screen broke and now I ordered a second one. I use it for tuning a 4-string bass in Drop B and it is the only one out of all the ones I have tried that effortlessly captures these frequencies

It does its job very well, it has been used on many different strings and has given accurate readings every time.
The only negative thing about its design is that the silicone cover on the bottom of the clamp keeps coming off - a small thing of course, but to prevent any instrument from getting scratched, it's a good idea to glue it back on (in case someone else encounters the same issue).
The fact that it automatically opens and closes is great, I don't think it necessarily needs improvement by having a simple switch, but it works very well.

The most practical tuner I have ever used. It automatically turns on when you hold it on the guitar. No switches. It tunes any instrument you want without any additional adjustments. If you leave it on the guitar, it shuts off by itself after some time, so the battery doesn't get drained. I have had it for several years.