An empty (american) Heineken "Keg", with the top in place, weights 35 grams. It is about 15cm tall and 8cm at the widest. A Fosters is similar. If your ~700ml beer cans are similar in size and weight, I would assume the thickness/strength is the same. All are aluminum. You can tear them easily, once started, with your fingers, like paper.
A Fosters is very flexible. A Heine gets it strength from its shape and the "ribs" at each end.
So you may have what you need right there in Finland.
But, if not, then asking for a "22 ounce Heineken Keg" at liquor and beer stores is all you need to do. The clerk will either know Exactly what you are looking for ...or not. In my small town, 3 out of 4 clerks are mystified, and the 4th will say "not until summer". In New York I suspect they are available year around.