Pagers Invented in 1921, pagers were used by the Detroit Police Department when they successfully put a radio-equipped police car into service. (5 янв 1921 г. – 11 авг 1925 г.)
Добавлено на ленту времени:
Дата:
5 янв 1921 г.
11 авг 1925 г.
~ 4 years and 7 months