CHRIS KNAPTON / SCIENCE PHOTO LIBRARY CHRIS KNAPTON / SCIENCE PHOTO LIBRARY
Mobile telephone keypad. Close-up of the external and internal parts of a mobile telephone keypad. In the complete telephone, each key (white) lies above a sensor (gold and black circles) on the keypad's circuit board, which passes on a signal when the key is pressed. Mobile telephones use microwaves to carry call information, and so their use is not hampered by wires.
Model release not required. Property release not required.