The CBE 12v Battery Test Panel in dark grey is perfect for checking the battery strength of any Caravan, Motorhome, Campervan, Boat or indeed any vehicle where it is important to keep an eye on your leisure battery. The CBE uses no power at all at rest, when the button is activated it shows the battery strength immediately with four clear LED lights, Red-Low, Yellow 1- Getting Low, Yellow 2- Almost Charged, Green-Charged.