Manufactured in Japan by the Mitsui Metal Craft Co., their sub-miniature lathe M.M.A. Model SM-3 was described by them as thus: 
"All metal
Ordinary lathe machine model
Scale 1/10
Mini Mini Machine
Ultra-Compact Desktop lathe" that could be used for "educational material, or as a stylish interior decoration"  - which sums it up pretty well. While the centre height is unknown - but would have been around 1.5 inches - the capacity between centres was stated as 3.3 inches - though from the pictures below, it does seem to have been a little greater than that..
The makers claimed that the lathe could turn brass with a diameter of 2 to 6 mm (0.08 to 0.24 inches) and also handle copper, wood, bamboo, plastic, hard synthetic resin, and other similar softer materials..
Fitted with an 18W DC motor flange mounted against the headstock's outer face and fitted with a noise-suppression function, the lathe was run through an adaptor intended to be fed from the  standard Japanese household electricity supply of 100-120 volts AC 50-60 Hz. It appears that the spindle ran at a single speed of 3000 r.p.m. and carried a chuck intended to hold drill bits. This fitting is unsurprising for sub-3-inch diameter conventional 3-jaw chucks are impossible to obtain for a reasonable price - if at all.
The carriage - topped by a single cross slide holding a 4-way toolpost - was moved by an exposed feed screw, positioned on the centre line of the bed, and turned by a handle at its tailstock end.
While the paint finish appears to have been reasonable, that of the chrome-plated metal parts was poor, a surprising thing to find on any Japanese-made machine tool. By way of contrast - and shown at the bottom of the page - the miniature American ManSon lathe had an overall finish of very reasonable quality. The Mitsui Metal Craft Co. presumably had nothing to do with that other Japanese Mitsui Company that made jig borers.