Thule Atlantis 780 (480 litres), KAMEI Husky (330 litres), Kar Rite Odyssey 320.  In each case the roof box is the full size of its carton
KAMEI have a reputation for being conservative about capacity, Thule and Karrite swing the other way. Look at these pictures that show (L to R) a Thule Atlantis 780 (480 litres), a KAMEI Husky (330 litres), a Kar Rite Odyssey 320. In each case the roof box is the full size of its carton. Seeing is believing.