The crank parts are missing to open and close the window. Not sure what brand as the windows are very old.
Casey from SWISCO responded:
September 9, 2022
Hello,
I would recommend starting by comparing the 39-094 and 39-095, as well as the 39-150 and 39-151 Andersen operators to your assembly. If one of these operator pairs matches yours, then you should be able to use the 39-154 cover and 39-286 handle. Thanks for posting!