Goal Zero Nomad 20 Solar Panel Built-in junction box with smart-charging chip, allows you to power handheld USB and 12 Volt gear from the sun Patented chaining technology combines Goal Zero Nomad panels for faster charge times Highly efficient mono-crystalline solar pumps out more power per square inch. Optimal Operating Temp: 0-120 F (-17-48 C) Pair with any Goal Zero power pack (sold separately) and charge gear day or night Foldable and portable for use anywhere