This is the Motorola DynaTAC series of mobile phones, commonly known as "Big Brother". This is a product of the first generation (1G) analog cellular mobile phone system era, and is the first mobile phone that can be hand-held by users in commerce. Its large volume, square shape, because it resembles a brick and is vividly called "brick machine". Equipped with a long retractable antenna. The phone was released on March 6, 1983. When it was released commercially in 1984, it sold for as much as US $3,995, which was the exclusive product of wealthy businessmen and celebrities at the time. Its talk time is very limited, it takes about 10 hours to fully charge, but it can only be raised.