I have the same model but seems to only work on presets?

This dryer was given to me but without the instructions. There are three presets on the dial which all work but are for 10min, 20min and eco. Even the eco setting seems to be on a timer but is it meant to run on that setting until the clothes are dry? There is a chart on the left giving times for differenyt loads etc but no timer setting only delay timer.

Thanks in advance