This wrist fitness/sleep tracker is about 9 years old but I think you can still get the software to go with it on your Android or iOS phone. Xiaomi Mi Band. I'm not sure that these devices are very accurate with sleep monitoring. Think it was still working when I last used it. Seems to be taking charge now. I have two different wrist straps and the connector to charge it.
If anybody would like it and would have a go to see if it can work well for them then collection from Dodleston please.
Thanks Nicola

Mi band wrist fitness tracker (old) (Dodleston CH4)