Japanese instruction manual is included, so it is safe for beginners. Charge controller for solar panels up to 12A. It has all the functions you need to automatically manage the solar panel and battery. This charge controller can be used to track the situation with the "Charging", "Output", and "Charge Level" light. Specifications: Rating: 12A, Size: 4.7 x 3.9 x 2.4 inches (120 x 100 x 60 mm); Weight: 7.1 oz (200 g); 12 V can support up to 144 W; 24 V supports up to 288 W; Built-in function; Automatic recognition function for 12 V and 24 V V overdischarge prevention function; Voltage protection