.
This must have been the TOW missile I saw demonstrated in a video;
" TOW 2B or BGM-71F is a top-attack missile. It appeared in 1987. This missile explodes above the tank to penetrate its thin top armor. In concept it is similar to a Swedish RBS 56 BILL. It has a maximum range of 4 200 m. Its warhead weights 6.14 kg
Armoring up top, bottom or both, eaual to frontal armor, would make almost any tank too heavy.
But of course, they now have reactive armor and the Israeli designed "Trophy" system, that explodes most projos, before they strike the tank.
Always has been a see-saw development battle..improved tank killer, followed by improved tank protection..