The F3 had a few dedicated buttons for opening the address book (top right), canceling any action (the red button), dialing the currently displayed number (the green button) and an "action" button (top left). A few more functions were available by shortcuts: When making a call, pressing the action button twice switched the loudspeaker on/off, while pressing up/down controls the speaker volume. The same button used in standby toggled voice prompts, while pressing up/down controls ringtone volume. When the phone rung, due to incoming calls, the ringer could also be silenced by pressing up/down. All activated features (set alarm clock, activated vibration mode, roaming, ...) were indicated by simple icons in fixed positions in the top row, and every successful action acknowledged by an "OK" icon flashing on and off a few times. The only context-sensitive button was the action button which was used for "OK" on options as well as choosing a number or address book entry when writing an SMS or for answering a received SMS.