Here is some info from a past auction for the 850(BL), mine is the 850H(R)
Up for consideration is an AM-FM Stereo Cassette Player by Sharp, Model No. JC-850(BL). This was one of Sharp's high-end products, made of all metal with chrome trim. The mechanical parts throughout are of the same quality craftsmanship, such as brass spindles and pulleys, metal tape transport unit base, metal cassette compartment hinges and Anti-rolling mechanism. It is a small unit, but heavy. The dimensions are 4-1/2 inches long, 2-7/8 inches wide and 7/8 of an inch thick.
