Round Solar Panel Skill Badge consists of a solar panel epoxied into a round disc 55mm diameter (about 2.2 inches). There is a sticky foam pin back, so you can attach to the back of the panel to mount it onto a backpack, jacket or sash.
The badge is also a perfectly functional solar panel. There are 10 slivers of solar cell inside for a 5V rated voltage in sun. The output is about 40mA when in bright sun, less in shade or cloudy weather. You can use this to power small, low power projects with a small low power microcontroller or chip and maybe an LED.
The epoxy coating makes this panel rugged and waterproof on the front. The back has points for soldering. If you want to make this fully waterproof you'll need to dab waterproof epoxy onto the back to cover the solder points once you've attached wires
Adafruit Learn Link (Skill Badge Requirements: Solar)
Adafruit Web Site: