Features Under the setting of the normal state (i.e. the digital tube flashes). Battery low voltage shut-off switch, the S1 button acts as an upward regulation voltage (adding a key) and the S2 button as a downward regulation voltage (reducing the key) S1 undervoltage setting (negative wear stop). Press the S1 button at normal display voltage to display the low voltage value. Press and hold the 51 button to stop the flashing of the digital tube, and adjust the undervoltage value with the S1 and S2 buttons. S2 surge setting (charging start). Press the S2 button at normal display voltage to display the surge value. Press and hold the 52 button to stop the flashing of the digital tube, and adjust the surge value by pressing the S1 and S2 buttons. In the normal state of power on, press and hold the S1 and S2 buttons at the same time. The digital tube displays 888, i.e. the original factory setting is successfully restored. Size: 79 x 43 x 27 mm (length x width x height), adjustable parameters, memory retention, extended battery life Functions: This is a low voltage switch used to shut off the load when the voltage drops below a set value. When the battery voltage rises to a set value, the module automatically switches the load back on. Designed with an LED indicator that shows if the battery is under voltage. The value for the on/off voltage can be adjusted by simply pressing the buttons. With this controller, you can protect the battery from deep discharge and extend the life of the battery. Technical data: Suitable battery: 12V memory/lithium battery Control current: 20 A. Control Accuracy: 0.1V Voltage error: ± 0.1 V. Size: 8 x 4.3 x 2.8 cm / 3.1 x 1.7 x 1.1 inches. Weight: 41g (approx.) Reset to factory setting: In normal state, press and hold the S1 and S2 buttons. Press buttons together until the display shows 888 to restore the factory setting. Package includes: 1 x battery low voltage regulator. Package List