The Mattel Aquarius II had exactly the same characteristics as its predecessor, the Mattel Aquarius.
Its only enhancements were the RAM (20 KB instead of 4 KB) and the mechanical keyboard. In fact, the Aquarius II only had 4 KB of built-in RAM but was supplied with a 16 KB RAM cartridge extension.
Another difference is that the Aquarius II came with Extended Basic built-in.
Mattel gave up the computer market and sold all the rights and computer stocks to their manufacturer, Radofin, before the Aquarius II was even launched. All the Aquarius II were thus manufactured and sold by Radofin.
A special version of Logo, called Aquarius Logo was developped for this computer.
An Aquarius III was planed, but never saw the light.