What’s the best resource for accurate watch information

Hi guys. So I bought my gf a Tissot PRC 200 chrono the other day. She constantly wears it in the water, as a result the leather band has been destroyed. She asked me to replace the band for her so I want to get either a nato or rubber. Will take recommendations on that too. My problem is I am trying to determine the band width. However, I have seen sites that say it 15mm, 16mm and 19mm. Note, this is for the same model #. So where is the definitive resource for watch specifications?
Also…

What's the best resource for accurate watch information