Features: Backlight control-Short press the key to turn on or off the backlight. Reset Energy-Long press the key over than 3 seconds can reset the energy. Current Indication-Current has direction indication, if there is "-", it means current is reverse direction, otherwise it is forward direction. Energy Indication-Energy has direction indication, if there is "-", it means the energy is reverse direction, otherwise it is forward direction. The energy direction is rated according to the current direction, if the current is positive, the energy will increase, maximum is 999kwh, overflow will be maintained unless you reset it. Package Includes: 1 Pcs DC Digital Battery Tester . Specifications: Material: PBT (high temperature resistant) Voltage measurement range: 0-300V Current measurement range: 0-300A Type: 50A host/100A host/200A host/300A host note: Please allow 0-1cm error due to manual measurement. Make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!