The balance function can be executed before/after battery , or during battery charging process, to battery pack keeping in excellent condition. Safe and convenient: it supplies instant voltage reading and indicates abnormal cell immediately. Allow Li-Polymer/Li-Fe 2-6 cell balancing and discharging. With its JST connector for external power, the balancer can measure voltage of receiver battery. The big LCD screen can show 6 cell batteries' condition. Only 3 control keys for easy single-handed control. Thermal design on the backside for ventilating and preventing overheating. Detailed instruction sheet is included. Small size and light weight, it is easy to carry. Measurable battery type and amount: Li-Polymer/Li-Fe 2-6 Cell (standard voltage 7.4V-25.2V using divided voltage connector) Receiver battery 1.2V-12V DC (Not battery type limit, but need external power 7.4V-25.2V, use JST connector) Balance voltage setting range (lower limit): 2.0V-3.9V (pre-setting value 3.3 V) Discharge voltage setting range (lower limit): 3.0V-4.2V (pre-setting value 3.9V) Weight: 121g colour: Black Material: plastic Package Contents: 4 x Battery Balancer Only the above package content, other products are not included. Note: Light reflection 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.