Description: The battery is being charged and discharged continuously during the course of using. Its capacity reduced can cause the failure of starting the automobileengine. It is a good instrument to measure the battery's voltage. Specifications: 1) External 12V or 24V 2) 20Ah-200Ah or 30Ah - 300Ah 3) Size: 300 x 140 x 185mm Outer packing: 4pcs/ctn