Size: 39x39mm Power: 0.25w Average Voltage: 0.5v Average Current:0.4A Effeciency: About 17% Connection way: the blue side connect “-” , white side connect”+”. If have any problems,Pls contact me first, don’t leave negative feedback and open dispute,thank you! because we will solve all problems . in order to ensure enough power,it is better to use solder strip , copper strips to connect. Package include: 100pcs solar panel (39x39mm) Note: we can Customize the size for you as your requirement. Attention: some pieces panels come with spots on side as production process can’t avoid. But don’t worry, it works still perfectly on power and voltage…if you are professional on it,will be ok. If you very mind the appearance, PLS don’t buy it ,thank you!