The Plus Four Wristlet Route Indicator, a British product from the 1920s, is a scroll-map navigator in the shape of a watch. It came with tiny interchangeable instructions that you scrolled manually to see which roads to take when driving. More about analogue ‘GPS’ devices below.(980 × 1195)

The Wristlet wearable was sold with a core set of 20 scrolls spanning various routes, most of them revolving around London, with more available for order from the manufacturer. Switching from one of the preset destinations necessitated stopping and swapping out scrolls along the way. Drivers or passengers would manually wind a dial on the side to keep the map moving along with the progress of their journey. 

[More information here](https://www.dannydutch.com/post/before-sat-nav-wristlet-route-indicator-iter-avto)

This is so frickin cool it’s a wonder that they weren’t more popular.