HTC One M9

Several functions are associated with On/Off:

Press On/Off to turn your phone on or off.

Press On/Off to turn on the screen lock.

Press and hold On/Off to access flight mode.

Several functions are associated with the Volume keys:

Press the Top volume key or the Bottom volume key to adjust the ring volume.

Press the Top volume key or the Bottom volume key during a call to adjust the volume.

Press the Top volume key or the Bottom volume key to silence the incoming call alert.

Connect the charger or data cable to the phone socket and to a wall socket or your computer's USB port.

Connect the headset to the headset socket.

Point the camera lens at the back of your phone at the required object to take a picture or record a video clip.

Point the camera lens at the front of your phone at the required object to take a picture or record a video clip.