Bought two mecatwin 30 heads, for converting even more hotshoe-flashes into armatar-frankenflashes. Does anybody know the J/s (W) rating for these? I guess the GN is 30?

There is a scale on the back on one of them stating that 1.9 m 'Entfernung' would require 'blende' 22 with 21/10 DIN film. So would I be right that ASA 100 film would require f/41.8 at 1 m, hence GN would be roughly 42? Hmm. Suddenly the mecatwin 30 name doesn't add up.

Here's a photo if you don't know what I'm talking about: