How do I determine the exact diameter of my product?

Here you will find a “diameter meter” document. If you print it, you must ensure that you do not scale it. A circle is drawn on the document, if exactly a 2 euro coin fits in here, the scale is correct. Cut the meter on the black line. You remove the caps under your seat and place the “diameter meter” in the tube leg, until you cannot continue without distorting the paper. Now you can read the correct diameter.

With this tool you can determine exactly which product you need.