battery holder: Battery connector type: Parallel Overall size: 78 x 40 x 21 mm (width x height) Cable length: 11cm Bore diameter: 3 mm / 0.12inch Mounting hole distance: 55 x 19 mm / 2.2inch x 0.75inch (L x W) Material: plastic, metal Color: black Setting: 2 x 3.7V 18650 Battery (battery not included) module: color: blue Material: PC + metal Solar panel input: 4.4-6V Max charge current: 500mA Interface: 2-pin JST connectors(or PH2.0) Short circuit protection Continuous Charge Current Up to 500mA Battery status indication ( Red: Charging , Green: ) Support USB Charge (Micro-USB Connector) Size:2cm x 4cm Package Contents: 1 x module 1 x battery holder Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. 2 PCS Electronic Accessories: 1 x module & 1 x battery holder The output of the Solar Charger is intended to charge a single polymer lithium ion cell. The load should be connected in parallel with the battery. By default, the Solar charge comes set to a maximum charge current of 500mA with a maximum recommended input of 6V (minimum 4.4V). It's recommended that batteries not be at their capacity rating. This is a super mini Solar Lipo charger based on the CN3065 - a single lithium battery charge management chip. This Solar charger provide you with the ability to get the most possible power out of your solar panel or other photovoltaic device and into a rechargable LiPo battery. Set-up is easy as well, just plug your solar panel into one side of the Solar charger and your battery into the other and you are good to start charging!