The S90 is Doogee's first rugged smartphone that comes with a selection of modules similar to Motorola's mods. These include a high quality night vision camera, a 5,000 mAh powerbank, a walkie-talkie and a game controller. Additionally, the casing of the S90 is made of military grade metal and polycarbonate, so it can withstand extreme conditions.
https://www.notebookcheck.net/Doogee-launches-S90-modular-rugged-smartphone.410201.0.html