Basically unlocks & locks the window. Not any markings I could find.
Tom from SWISCO responded:
July 15, 2022
Hey there! This old window lock hasn't been made in a long time, but I believe you can use our 38-097 and 38-098 as substitutes. Just note that you'll also need a new 38-079 keeper, since these locks won't be compatible with your old one.