Lindström Filter Pipe
Lindström, or Lindstrom as some says and writes, was a German company which started in the late 50’s and invented the brass ferrule patent. The ring had 1 hole, or sometimes up to 4 holes of different sizes, which you could turn matching over an airhole in the stem. An arrow on the stem marked the place where they match. In this way you could regulate the mount of air to add to the smoke, resulting in a dry and cool smoking pleasure.