Another Rolfix II question

Greetings everyone.

I have another question regarding my newly acquired Rolfix II.

On the top plate of the camera just to the left and behind the shutter button is a slider marked with what appears to be the letter T with an arrow pointing to the back of the camera. It only moves a small amount but.i am wondering what it of for?.

Does anyone have any idea?

Thanks in advance

Just guessing, it may be that if you set the shutter to 'B', this slider lets you lock the button down for a 'T' exposure. 'B' shutter is where the shutter stays open as long as you hold the button down; with 'T', you press the button once to open the shutter, and it stays open until you press again to close it. A switch like this to convert 'B' to 'T' is not quite as good as having 'T' built into the shutter, because you're quite likely to shake the camera while operating the slider; but in reality, most people never need 'T'.

This Solida III (at Flickr) has something similar. I'm certain that's what it does. Try setting the shutter to 'B', press the shutter button, and set the slider while it's down.

Franka Solida III (1954) by strind1977