a pseudo-russian binoculars

Hi, I bought recently a binoculars (it suppose to be russian but
actually they seem to be chinnese).

Who sell them me said that those are 30x50. But they just has this
label:

99990X99990 (Z)
Sehfeld
8m aut 988000m

What does this information means?
There exists a formula to convert from 8m/988000m to something like
10x50 or 30x50?

I compared them with another (professional) binoculars 10-30X50 and I
finally discovered that my binoculars are 10X50

Thanks.