14
1.
Custom buttons
: user-defined key in the secondary development
2.
Bar code scan keys:
Press this key to scan the bar code
3.
Headphone jack
: Can insert 3.5 mm headphones
4.
Charging and USB interface
:
Sending and receiving data by USB data line
or charging by Power adapter
4. Charging
and USB
interface
3. Headphone
jack