In our ground floor office we have old aluminum sliding windows whose pane does not seal well enough to prevent the wind from entering through the space inbetween. This 3D printed part solves the cold-wind-penetration issue :)This is to be used on the bottom part of the window, if you are looking for the piece for the upper part of the windows check out thingiverse.com/thing:12942/Just measure your Aluminum window pane width and adjust the printed part size to fit snugly.Just get some insulation tape compatible with of aluminum windows, cut two small strips and slide them into the slot.Put the piece in place and mark it with a pencil.Remove the windows and put a screw to fix it in place. (if you don't have self drilling screws mark it with a pencil and use a driller to make the screws hole first)Put the windows back on and enjoy your seeing evidence of the wind blowing outside without any breeze penetrating into your room.