Using The Call Log - Lenovo VIBE K5 User Manual

Mute: turns the microphone on or off.
Record : starts or stops recording the call.
Dialpad : displays or hides the keypad.
Speaker : turns the speaker on or off.
: ends the call.
You can also press the volume button to turn the volume up or down.

Using the call log

The call log contains missed, outgoing, received, and all calls entries. You can press and hold
a call log entry until the options menu appears, and then tap an option. For example, you can
tap the Add to contacts option to add the entry to the Contacts list.