The Garmin Instinct 2X Solar in Whitestone is the larger 50mm sibling of the Instinct 2 Solar family, built for serious hikers, mountaineers and multi-day expedition users who want the biggest possible solar panel and the longest possible battery life in a rugged watch. Its expanded solar lens produces around 50% more energy than the standard Instinct 2 Solar, delivering up to 40 days of smartwatch-mode battery from charge alone, or effectively unlimited smartwatch battery life with just 3 hours of direct sunlight per day. In GPS mode it runs up to 60 hours on battery alone (145 hours with solar), up to 40 hours with all satellite systems active (65 hours with solar), up to 27 hours with all systems plus multi-band positioning for maximum accuracy (36 hours with solar), and up to 150 hours in max battery GPS mode (effectively unlimited with solar). It uses a rugged 50mm fibre-reinforced polymer case, is water rated to 10 ATM, and is tested to US military MIL-STD-810 standards for shock, temperature and water resistance. Beyond navigation it includes a built-in flashlight, multi-band GNSS support, and Garmin's full suite of health and wellness sensors. This is the right choice for anyone who wants the absolute longest battery life and largest solar-charging surface in the Instinct range and doesn't mind the bigger 50mm case — buyers who prefer a smaller wrist profile should look at the Instinct 2S Solar instead.