I don’t think this company still exists.
At one time you could buy Mizuho single band SSB handhelds for many bands up to 2m including many HF bands. I owned the 2m 200mW pep version (MX2) and managed to work some decent SSB DX with mine mostly with a 1/2wave whip on the rig. The main issue was the poor battery life, so I tended to use an external 9.6V battery.
My rig was used in the main with a homebrew 2m-10m transverter and I worked all over the world on 10m with just the tiny Mizuho rig on the desk.
If I remember right I covered the CW and main SSB parts of 10m by having a couple of crystals in the transverter. Somewhere I still have the transverter, although it has not been used for years.