GPS Watches combine the functions of a wrist watch and a GPS tracker. They have varying additional health and fitness functions.
They are ideal for people with a tendency to wander and/or get lost, or anyone with a significant vulnerability, for which other family members may want / need to know where they are, for their own safety.
The Health and Fitness functions may provide a convenient ancilliary function to help with the Wearer's acceptance of the watch.
GPS watches are bulkier than non-GPS watches, without question. The additional bulk comes from its battery size, to provide 2 days battery life, and the physical dimensions of its antenna and circuit board.
They come with a SIM already installed, which does not support or allow phone/voice functions. If these are required, an alternative higher cost plan SIM can be supplied / arranged.