LED indicator: "" LED is charging status indication, "OK" LED is fully or in constant voltage mode.Wide range of usesHigh safety performanceEasy to understand and easy to operateBattery overvoltage protection:4-Cell(4S) 16.8V version:Input voltage: DC 3-6V (recommended DC 3.7V 5V)Input Current : 4A(4A Version)Charging voltage: 16.8VCharging current:1.12A(4A Version)Working environment temperature: -40 to +85Dimensions: 39x18x 6.3mmColour:redMaterial:PCBPackage Contents:1 x ModuleOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.