This the TRC-210,  one of Radio Shack's earliest 40 channel walkie-talkies.  It is still the size of a large "brick", which takes 8 "AA" (or 10 Ni-Cad) batteries to operate. It features a Volume, Squelch, Battery/Transmit power meter, and 40 channels with a battery saver feature which extinguished the LED channel display after a few moments of a channel change or pressing a display button. This radio was also equipped with a Hi/Low power switch and an external 5 pin DIN mike jack, which allows it to use an external mike (You should've heard it with a D-104).  It also utilizes the Shack's efficient center loaded antenna, and capacitive ground panels. This resulted in this unit having fairly good range for a handheld unit. A far cry from the pitiful range obtained by newer units with "rubber duck" style antennas. This unit came into my possession, like many others, thru trades for other radio work.