Unknown OHTO pencil

[Gunther]

Many years ago I bought this OHTO pencil.

It has no marking except “OHTO” on the clip. Does anyone know the model number?

By the way, the grip is unusual because the pattern is under a transparent rubber layer.

[drifand]

OHTO Piston SP-15. There’s a matching ballpoint.

Pardon the mistake (SP-20) in the post…

[Gunther]

Wow, thank you!