The size is about 38mm or so

This watch pairs with an app and works as a step tracker (the inner circle goes from 0% to 100% showing how much you've accomplished based off a value you can define in the companion app)

Including several straps that can be quickly swapped to change the look and feel of the watch

One advantage is that this step tracker doesn't consume a lot of power through LCD displays, so the battery lasts for 1 year or more easily