English: Guide tube for a cord used to raise and lower a roller shade. The s-bend in the tube suggests the individual who implemented the installation had no knowledge of the capstan equation. A single, gentle bend would have resulted in considerably less friction on the cord, reducing the force required to raise the shade.
{{subst:Upload marker added by en.wp UW}} {{Information |Description = {{en|For rolling a curtain up and down. }} |Source = My own photo. Some editing in GIMP. |Date = 2012-10-19 |Author = Laelele }}