Hitachi TH-621
The TH-621, Hitachi's first shirt pocket radio and one of the company's first transistor radio products, went into production in September 1957. Pictured on this page are the ivory and coral colors, but there was also a light gray version with a white reverse-painted tuning dial.
This is also a radio with a secret!
72 x 113 x 32 mm (2-7/8" x 4-1/2" x 1-1/4")