SNAN Portable 21W Dual USB Solar Charger with Foldable Solar Panel and Stand SMART CHARGING TECHNOLOGY - Built-in intelligent chip detects the remaining power of your devices and matches optimal current output automatically. Two USB ports provide up to 2A per port under direct sunshine and charge your devices very fast, even faster than being connected to a wall port in really hot summer day. HIGH CONVERSION RATE - Solar power conversion efficiency can reach to 23.5%, giving you a peace of mind whenever you need power to charge your devices. Sometimes you would forget to charge your power bank. This product offers you a far better solution than a battery, as it's also more environmentally friendly. USEFUL STAND - The unit has two stands attached that can be pulled out to stand the unit on its side to collect more sunlight throughout the day. It gives you the best angle for charging, as it will allow the most direct solar radiation. THOUGHTFUL DETAILS - It folds up 11.46.41.7 in and weights 1.9 lbs, fits great in a backpack. There are 4 snap links for attaching charger to backpack or other item. The charging ports were securely fastened to the inside of an internal pocket that keep the phone safe inside the pocket in the event of rain and strong sunbeam. FULL PROTECTIONS - Industrial-strength PET polymer fabric makes waterproof and dust-proof possible, great for any outdoor activities. SNAN solar charger covered with super 18 months warranty and friendly customer service.