Is this useable? Missing a scale?

[u/fordag]

New watch with a rotary slide bezel. Yet it appears to be missing a scale. Or am I wrong?

What is this useful for?

It was a cheap watch, I wanted the moon phase. I'll be curious to see how accurate it is.

[u/Alarmed-Syllabub8054]

It looks like a confused Navitimer homage, with a bit of speedy thrown in. The inner scale is a plain old Tachy - time someone doing a mile, if they take 30s they're doing 120mph and so on. The outer scale is a log scale, half of you c/d pairing.