FeaturesDustproof & waterproofBuilt-in ammeterApple & Android compatibleWith this lightweight and ultra-thin Bear Grylls 21W Portable Solar Charging Mat, all you need is sunlight and a USB cable to charge your device.Solar power technology - enjoy the great outdoors and stay powered up using the limitless power of the sun. Simply fold out the solar panels or attach to your pack to connect and charge using the two USB ports.Built-in ammeter- the built-in ammeter displays how much charge you’re receiving from the sunlight. Just plug in your device and the ammeter calculates the current USB amp output being generated by the solar panels.Fast charging technology - the fast charging technology will have you charged and ready-to-go in no time. With enough direct sunlight, the two USB output provides it\'s fastest possible charging speed up to 2.4A and is compatible with Apple® and Android™ smartphones, tablets and other USB-charged devices.Lightweight and ultra-thin - the compact design and durable, stainless-steel eye-holes built into each corner makes attaching the mat to your backpack or anywhere super easy. The ultra-lightweight and thin mat can bend to fit comfortably into and over your daypack.Durable and heavy-duty - the three solar panels are sealed into the weatherproof material, ensuring the mat is able to withstand any situation, rain or shine.IP64 Dustproof and Waterproof - the mat can withstand any weather conditions with its rating of IP6 Dustproof and IP4 Waterproof.