Adox/EFKE 25 -the 25 in the name was the Tungsten speed, it had a Daylight speed of 40-50 EI which is the same as I used Tmax 100 at (50EI), in fact I exposed both the same and developed for the same time sometimes together.

So I never thought it was the slowest conventional film that to me was AP25 & later APX25, and also PanF

Ian