Features: Automatic Identification System Voltages, 12V/24V auto recognition. Humanized LCD displaying and double button operation of man machine interfaces. Working Storage Function: record the total running time of system, record timers of error during running time, record time of full charged battery. Accurate temperature compensation, correcting the charging and discharging voltages automatically, improving the battery. Builted in overheating, overcurrent, short circuits, open circuits protections. Specifications: Materials: ABS Current: 10/20A/30A(Optional) 10/20A size: about 95x133x30mm/3.74x5.24x1.18inch 30A size: about 115x150x30mm/4.53x5.91x1.18inch System Voltages: 12V/24V Working temperature: -20~50℃ Package Includes: 1pc Solar Charge Controller note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color.