I have a question about two objects that appear on the conning tower side, a circle and a square crisscrossed horizontally and vertically. They are pictured on page 20 of Vom original zun Modell and labelled as Notausblaseluft (square) and Raumnotluft Bb. (circle) in a diagram titled \"Turmumbau - Originalausfuhrung\". What am I looking at here? Thanks, in advance for the feedback.

Best Regards, always
Will