These panels come to us from Voltaic Systems, makers of fine solar-powered bags and packs. These are waterproof, scratch-resistant, and UV-resistant, and they use 10 high-efficiency monocrystalline SunPower cells with 22+% efficiency (praise the sun!). Each cell has a nominal voltage of 0.5V so we call this a "5V" panel. Note the datasheet has it down as a 6V panel, because at max-power-point it will give you 5.9V

• They output approximately 6V at 50 mA peak via two solder-able pads on the back. The panel is constructed with ETFE (Ethylene Tetrafluoroethylene), making it extremely durable and resistant to environmental elements, a superior upgrade to PET or laminate solar panel construction. They can easily stand up to typical outdoor use, including being dropped and leaned on. 
• Unlike the larger panels, these don't come with a connector. Instead, there are two pads on the back. We recommend soldering two wires and attaching a 2.1mm terminal block to connect. (Or you can cut off the alligator clips from a 2.1mm-to-clip adapter)
• If you want to use this to charge a battery or run your project, check out our optimized Solar Lithium Ion/Polymer charger!

Specifications:

• Features
• Waterproof (IP67)
• UV-resistant (5-7 year life)
• Durable and lightweight
• High-efficiency monocrystalline cells: 22+%
• 2x Solder Pads
• Size and Weight
• 52mm x 52mm x 3mm
• 12.1 grams
• Construction
• Matte ETFE coating
• 1.5mm double-sided PCB
• Warranty
• 2-year warranty on solar panels
• For more warranty information, see the warranty guide

Documents:

• Datasheet
• Diagram
• Specification Sheet

Package Includes:

• 1 x Adafruit 5855 5V 0.3W Mini Solar Panel - ETFE - Voltaic P122