Braun KT4 transistor radio

The transistor was developed in 1947 by Bell Labratories, the first transistor radio was developed by Texas Instruments and produced by I.D.E.A. (Industrial Development Engineering Associates) of Indianapolis In. It was introduced in October of 1954. Sony bought the patent license and introduced theirs in 1955. 
 Braun was not to be left out and sold this model from 1960-62. More here.