BenQ Z2 - Manual (Page 41)

Using Your Phone 25
Making an Emergency Call
To call emergency services, enter 112 (the international emergency
number) and then press to dial the call. You can make an
emergency call even if your phone is locked or cannot access your
network, or there is no SIM card inserted, so long as you are within
range of a network of the type supported by your phone.
Dialing an Extension Number
After you enter a telephone number, long-press until "P" appears
on the display. At this point, you can enter the desired extension
number, and then press to dial it.
Speed Dialing
You must assign a number key as the shortcut for a particular phone
number in order to use speed dialing for that phone number. For
information on how to set up a shortcut, see page 54, "Shortcuts
Menu".
After you have assigned a number key to serve as the shortcut key for a
particular phone number, long-press this key when the phone is in the
idle mode to dial the corresponding phone number.