Fossil Gen 5 vs. Gen 5E What's the difference? Choosing between two smartwatches will depend on numerous factors, especially when you're dealing with two very similar wearables, like the Fossil Gen 5 and Fossil Gen 5E. While the design varies slightly, there are some bigger differences to be aware of here. Fortunately, both models are packed with plenty of new features that came with the latest software update. As for the key differences, the Fossil Gen 5 includes onboard GPS, 8 GB of storage, and a rotating crown for easy navigation. The Fossil Gen 5E is a lite version of the original model. You only get 4 GB of storage and you'll have to rely on connected GPS with your phone. While you have a side button, it doesn't feature the rotating crown. However, you will have two different case size options: 44mm and 42mm.