During World War II, the need for new buses increased to replace the ones that had been destroyed. However, because materials were needed for the war effort, bus builders had to manufacture vehicles from lower-grade components. Also, the British Ministry of Supply imposed guidelines on bus building and related activities. The Arab II was made in accordance with the Ministry of Supply's regulations, as such regulations were not yet fully withdrawn in spite of the war's end.
The bus was angular in shape to reduce the number of needed manufacturing operations. Its frame was made of unseasoned wood and was covered with steel panels. Because of this, the body of the Arab II did not last long in service. The bus was fitted with a Gardner 5LW diesel with manual gearbox and had 56 seats.
In 1980, one example of the Guy Arab II was donated to the London Bus Museum, where it is currently exhibited. It is the only remaining wartime utility bus of London, as others were eventually destroyed.