This is for the short 10cm FCC cable for the X360key that goes from the X360key to the USB dongle.
XK3Y USB dongle is not included.
For Lithium battery expansion board:
Battery capacity: 3800mAh
Maximum output current: 1.8A
Output voltage: 5.1V ± 0.1V
Standard charging current / voltage: 1.2A/5.0V
It's convenient to power on / off raspberry pi via battery swith;
It can last about 9 hours if only pi 3.
The Lithium battery expansion board can be also used on cellphone.
Note: You can still charge this battery even if the switch is turn off;