Please be kindly notedthe listed product is produced and distributed abroad and subject to the laws of its country of origin This tool can intelligent detection of the unbalance difference between adjacent battery packs can realize the transfer of high voltage to low voltage, so as to achieve the voltage balance between battery packs. Features: Stable Heat Dissipation: The open design can effectively dissipate heat, and it will not overheat when working, effectively prolonging its service time. It can automatically detect the unbalanced voltage value between adjacent battery strings. When the pressure difference value is0.1, it has three modes of continuous work, discontinuous work and stop work, and can balance the difference value is 0.03V. The surface of the circuit board has been painted, which can realize waterproof, dustproof and anti-leakage, and improve its safety. This tool is applicable to 3.7V battery packs and 3.2V lithium battery packs, has wide applications. K1 means keep active balance on, the middle means when the battery voltage is lower than 3V, turn off active balancing and sleep, K2 means turn off active balance and in to sleep. Specifications: Material: Printed circuit board Type: 4S, 8S (optional) Balance current: <2A Balance differential pressure: <10mV Balanced type: inductive active energy transfer Working consumption: <10MA Sleep power consumption: <500uA Package size: 4S: 55 * 45 * 16mm / 2.2 * 1.8 * 0.6in 8S: 83 * 55 * 16mm / 3.3 * 2.2 * 0.6in Package weight: 4S: 38g / 1.3ounce 8S: 70g / 2.5ounce Packing list: 1 * Active Balancing Module (Optional) 1 * Set Cable