An Obi is the belt that is worn with kimono. In Japan Obi are available in many different styles depending on whether it will be used with a formal or informal style kimono.
Many Japanese ladies will spend more on their Obi than their kimono. Often such an Obi would be more elaborate than the kimono it adorns.
In our Barcelona shop we usually have two or three formal style Obi though at up to 3 metres long and requiring certain knowledge to tie correctly we recommend our less formal models.