1、Compact \u0026 Lightweight Portable solar charger is 5.9 * 5.1 * 0.1inch in size and weighted 2.9oz, is small and light enough to fit into any camping backpack, hiking daypack, or emergency kit. 2、Efficiency \u0026 Stable USB Port Charging efficiency up to 2.5V/500mA max, with built-in voltage stabilizer, Automatically adjust current and auto-restart function, no need to connect again when passing under shadow or cloudy days. 3、High Energy Conversion Highest efficiency Monocrystalline Silicon Sunpower Solar Panel ensure a high energy conversion rate greater than 19.5%. 4、Wide Compatibility You can use this solar powered charger for any 5V electronic device like battery packs, cellphones, tablets, emergency light and more, or 3.7V rechargeable batteries. 5、High Durability Monocrystalline silicon and Epoxy surface seal, ensure long lasting durability, allows you DIY and attach it to fixed position. 6、Epoxy Seal, Durable Monocrystalline silicon and Epoxy surface seal, ensure long lasting durability, allows you to DIY and attach it to fixed position.