This product is 18 keys bamboo calculator. Using both solar panels and button battery.double intelligent power supply(generally using solar power, when solar battery have no electricity, use button batteries instead).Full bamboo carbonized natural color. Automatic Shutdown after 12 minutes no operation to entering power saving mode. 

Note:

1.The calculator design of 12 bits,the results don't round

2.When operation bits over 12,error handling.reset only by pressing the ON/AC

3.When inputting error,press the backspace key to delete bit by bit

4.The calculator automatically shut down after 12 minutes no-operation,then enter the sleep state.you can press ON/AC to awake it

5.When the operation result beyond 12 negative,negative sign does not show

6.Please avoid using it under the strong light.