Pyle PBT96 Instruction Manual page 8

For Hands-free Function:
 During the incoming call, When under music playing mode, C23S will
automatically switch to call function.
 Answer the phone call on your mobile or click the call button to Answer
 Again, Press the Call button to hang off
 Double press the play button to automatically call back
For charging Function
 C23S features Dual USB 3.4A to charge your smartphones & small tablets.
 To charge your USB powered devices, Plug one end of cable into C23S's USB
charging port and other end to your device.
 This model also supports to display the car battery voltage, so as to remind t
your car battery health status.Here is the instruction.
Lower than 12V: the car battery's voltage is low.
(If lower than 10V, the car battery need to change)
12V-13.4V: the battery's voltage is normal
13.4V-15V: the battery is on charging
15V or above: the battery is fully charged