According to a Twitter post by DongleBookPro which revealed the new Apple Watch Series 2 prototype. The Twitter account is known for documenting various tech prototypes.

The post indicated that the new watch has cellular compatibility originally supposed to be released a year earlier.  

While the cellular function of this prototype is the most crucial feature, it is also exhibited in an unannounced gold stainless steel finish. Apple did not release a gold stainless steel Apple Watch until the Series 4, which was released nearly two years later.

With the Series 2, the manufacturer dropped the 18K solid gold editions in favor of a ceramic model that was significantly cheaper. Only silver and space black was available in the stainless steel Apple Watch Series 2.  

According to DongleBookPro, Apple eventually dropped cellular in the second prototype of the Apple Watch Series 2 because the internal modem caused the device to overheat.

Even though the prototype depicted in these photographs was still in the early stages of development, Apple inscribed the words “Series 2” on the back above the crystal. It’s also using test software instead of watchOS, which has a whole different interface.

However, as many of you are aware, Apple only released a cellular smartwatch with the Series 3, but these prototypes indicate that Apple was already working on it with the Series 2.

And finally, according to the tweet, this proposal was shelved since the modem used in the Series 2 had a 60% failure rate and was frequently overheating.