Apple watch bands and sensors

[qwer81]

Hi guys, I would like information on the Apple Watch bands. Could non-original bands (those commonly sold on ebay or Amazon) cause problems with sports and heart sensors? In particular, I saw (in the photo, I don't yet have an Apple Watch) that the "Sport" bands have a metal part inside. Is there any sensor? Thank you

 

[FHoff]

There are no sensors in the bands. Just need to be carefull with 3rd party bands some fit better than others.

 

[Capeto]

Some might also be made of materials that may irritate your skin after wearing them for a while.