Features: This is power point track (MPPT) solar charger for lithium batteries. This MPPT solar charger provide you with the ability to get most possible power out of your solar panel or other photovoltaic device and into a rechargable lithium battery. Just plugs your solar panel into one side of the solar charger and your battery into the other and you are good to start charging. Solar power point track (MPPT) is to ensure that the light intensity change, photovoltaic cells output power, to make full use of solar energy. Power of sun with the CN3795 MPPT Solar Photovoltaic Charging Module 2A, advanced solution for efficient solar energy conversion. Specifications: Size:Approx.3x5cm/1.18x1.97inch Package Includes: 1Pc Charging Board note: 1.Please allow 1-2cm errors due to manual measurement, making sure that you not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual of the item.