You use an extension rod to lower a ceiling fan to the required height if your ceilings have extra height to them. These rods come in the same colours as the fans to match.
Please note that the Mercator Grange and stainless steel Mercator fans have a separate extension rod – to make sure you get the correct extension rod, simply find the fan you are purchasing and scroll down to find the section “You May Also Like…” to find the accessories to match the fan.