Features: This is an under-voltage switch controller used to turn off the power of a load when the voltage drops below a set value. When the battery voltage rises to a set level, the module automatically turns the load back on. Designed with an LED indicator to show if the battery is under-voltage. Both turn-off and turn-on voltage values can be adjusted by pressing buttons. This controller helps protect the battery from over-discharging and extends battery life. Specifications: Suitable Battery: 12V storage or lithium battery Control Current: 20A Control Precision: 0.1V Voltage Error: 0.1V Size: 8 x 4.3 x 2.8cm / 3.1 x 1.7 x 1.1in Weight: 41g (approx.) Restore to Factory Setting: In normal state, press and hold S1 and S2 buttons together until the display shows 888 to restore factory settings. Package Includes: 1 x Battery Under-voltage Controller