Seen on Twitter, an Apple Watch Series 6 with the test OS, which is quite rare.

Seen on Twitter, a prototype Apple Watch, between the 38 mm and 42 mm versions.

Seen on Twitter, something unique: a prototype Sport band for Apple Watch with a metal connector.

Seen on Twitter, an Apple Watch Edition prototype with an associated band.

Seen on eBay, a prototype of the Apple Watch Series 5. The unique feature of this model (sold for $80) is that the watch has notches to be placed on a demo iPad stand. This is quite rare on recent watches, as Apple mainly used this design for earlier models.

Spotted on Twitter, a prototype of the Apple Watch Ultra, which is obviously quite rare.

Seen on Twitter, a prototype of the 38mm Apple Watch Series 3… more or less.

Seen on Twitter, a product related to the Apple Watch: a Lightning to diagnostic connector adapter (AWRT).