The Kickr IV USB enabled portable solar charger is flexible, durable and lightweight. Other solar panels, such as monocrystalline panels, are placed on a glass backing, which makes the units extremely heavy, rigid, and fragile. Ascent Solar, who manufactures EnerPlex's Kickr and Commandr portable solar chargers, uses patented CIGS solar technology to place solar on a plastic backing, allowing our solar products to be flexible, durable & lightweight. The EnerPlex Kickr IV portable solar chargers can charge a variety of USB-enabled devices, like cellphones, GPS devices, action cameras and other small electronic devices. When using the Kickr IV, we recommend angling the solar cells directly towards the sun to receive the fastest charge possible. Providing twice the output of our Kickr II & Kickr II+ solar chargers, the Kickr IV is one of the most popular products for backpackers, campers and travelers. Lastly, EnerPlex is one of the only manufacturers whose solar is made in the USA. In direct sunlight, the Kickr IV should charge at the same rate as a wall outlet, so 2.5 hours for a phone or 6.5 hours for the Slate 5k.