We recently saw, in a sushi restaurant in Tokyo, a simple way of keeping heavy doors open: a large stone with the pull-cord for moving it tastefully wrapped around.
Now we have brought the idea over here, so that European doors can also stop slamming in the wind. Antique cobblestone with a 90-degree recess, padded with felt. The bottom is ground flat and covered with foam rubber to protect wooden floors.
Distance around edge approx. 18-20 cm, weight approx. 10 kg.