If you have an older iPhone that can't upgrade to iOS 12.2, you'll have to do a little more sleuthing. You won't see an entry for the model name, but you will have a model number. However ...
If you aren't sure which model Apple Watch you have, look for the model number in the Watch app on your iPhone. Search for the model number on the Apple support page to identify your Apple Watch. You ...
That's not a problem, though, because you can quickly find out your model name and model number in your iPhone's Settings app.