Microsoft Sculpt Ergonomic Number Key Pad Bluetooth 10 Key Model 1558 
THIS WILL BE SHIPPED WITHOUT A BATTERY.  YOU WILL NEED TO PURCHASE A CR2430 SEPARATELY FOR OPERATION.
And you will need a small flat head screwdriver to open the battery compartment. 

Photo showing the battery is only for reference.  Again, this will not be shipped with a battery.

Please review all photos for best visual description and measurements. Also, please ask if you have any questions. 

Thank you

(PID:06250-486-7038064-01631)