This is the Realistic (Radio Shack) TRC-99c. This large "brick" of a walkie-talkie was a 3 watt, 3 channel unit. This radio used up to 8 (or 10 NiCad) AA size batteries to get its power (12V), and this only added to its overall weight. Among its other features were a Volume and Squelch control, a separate mike and speaker, a battery/transmit power meter, external mike and speaker jack, and an "RCA" style external antenna jack. The unit was also made with a couple different antenna configurations depending on the year of manufacture. Some had a straight telescopic whip, while others used the more efficient center loaded telescopic whip, which was an electrically loaded 1/4 wave antenna.
I ran one of these briefly during the summer of 1973. In my desperation to rise above the limits of my 100 mW radios, I made the mistake of buying a second hand TRC-99 from Steve for the astronomical sum (for a 13 yr old living on an allowance) of $30. The radio transmitted ok, but had a weak receiver and, in fact, my 100 mW Midland 13-428 actually received better. Steve was not motivated to help me fix it, and I ended up cracking an I.F. tuning slug while trying to squeeze every little bit of receiver sensitivity out of it. After that, the receiver really became deaf and I ended up using my 13-428 Midland to listen, and then transmitting with the TRC-99. This ended up being an awkward but fairly workable situation until I accidentally shorted out the transmit final. I guess I just couldn't keep my fingers out of it. The radio then became a parts bin candidate in short order. I was then reduced back to 100 mW status for a few months before getting a new Midland 13-700 for Christmas.