What are "see through watches" called?
Those watches are called Skeleton Watches. A skeleton watch is a mechanical watch, in which all of the moving parts are visible through either the front of the watch, the back of the watch or a small cut outlining the dial!
True 'skeletonization' also includes the trimming away of any non-essential metal on the bridge, plate, wheel train or any other mechanical part of the watch, leaving only a minimalist 'bare' skeleton of the movement required for functionality. Often, the remaining thinned movement is decorated with engraving. This can be with or without a dial face that allows the user to see through to the movement.