Purpose: Battery charging control protection switch Set the starting voltage: in the normal display voltage state, pressing this button display the starting charging voltage; long the 3s digital tube flash; you can set the starting charging voltage value by starting or stopping the button Set the stop voltage: in the normal display voltage state, this button to display the stop charging voltage; and hold the button for 3 seconds, the digital tube flash; you can start or stop the button to set the stop charging voltage value Input voltage: DC 10-30V Output type: direct output Application field: 12-24V battery Material:PC+metal colour:Blue Package Contents: 1 x Charge Control Module Battery Protection Board Only the above package content, other products are not included. Note: Light 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.