Well this is interesting...
According to a new rumor, LG's G Watch could include a feature they didn't share when they announced the product. This "special hidden" feature will supposedly be a built-in non-removable SIM card.
The source of this story indicated the G Watch and its hidden feature will be unveiled at Google’s I/O 2014 in June. No explanation was given as to why this feature will be included. It's a bit unusual considering the G Watch is designed to require a smartphone for most of its functions. It's possible that LG is working on a variant of their G Watch which will be a standalone cellular device, just like Samsung's rumored Gear Solo watch.
We will keep an eye out for any further details regarding this strange rumor.
Source: BGR