twin-deck 3wayspeakers burglar-alarm led meter 8-inch woofers rare 1-piece powerful gold conion biggest Conion TC-999
This Conion Technisonic TC999 is an "upgraded" version of the Conion C-126F, with 6 speakers instead of 4. That seems to be the only technical difference. The other differences are just cosmetic. Both models have 8-inch woofers, 2 tape decks, and a burglar alarm. However the TC999 is gold in color, and has individual grills over each speaker, instead of the big square grills on the C126.
It measures 754mm wide, 400mm tall (not including the handle), and 148mm thick. It weighs 17.8 lbs (8.1 kg) without batteries. NOTE: There is another version of this box called the Epsilon TC-999 which doesn't have the burglar alarm. Instead, it has extra decals that try to look like a spectrum analyzer and a graphic equalizer.
The speaker trim rings can be removed for cleaning. The screws that hold them on are located inside the front panel. They are arguably the best-looking speaker rings ever made, because they have lots of angles and grooves to catch the light. 
What's not so cool is that the circuit boards block access to the controls, and must be removed if you want to clean them.
It uses a Sanyo LA4508 amp chip, which according to Sanyo datasheets is capable of providing 8.5 watts per channel. Bass output is very strong, and it goes loud. The mids and highs are not as precise as a Panasonic or JVC, but that's typical for a Conion.
The RCA input jacks are located on the front of the boombox, for ease of use. The inputs are labeled "Phono", but I could play a regular line-in source just fine, with no need for a phono attenuator.