This nifty little gadget has a chemical compound in its core which changes colour to indicate the UV intensity of the sun - the stronger the colour - the more effective your solarmonkey and solargorilla solar chargers will be at charging your device. uvmonkey will even keep you safe in the sun - if the colour on the chart shows as strong, put up your parasol and get in the shade! Made from the same tough, rubberised materials as the solarmonkey and powermonkey-eXplorer portable chargers - chuck it in your beach bag and head out into the sunshine! N.B. uvmonkey must not be left out in sunlight for more than a couple of minutes, as the chemical compound will permanently be dyed darker.