One of the most common questions we receive is about the size difference between our 30L and 18L waterproof backpacks. These two backpacks share a nearly identical design, making it difficult to distinguish the sizes from photos alone. To assist you, here is a side-by-side backpack size comparison.
LENGTH: 31cm  (12″)
WIDTH: 17cm (6 3/4″)
HEIGHT (backpack closed): 54cm (21″)
HEIGHT (roll down extended): 68cm (26″ 2/3)
LENGTH: 29cm (11 1/2″)
WIDTH: 14cm (5 1/2″)
HEIGHT (backpack closed): 49cm (19 1/3″)
HEIGHT (roll down extended): 63cm (24 4/5″)
Here, you can see both backpacks side by side. The size difference is not significant but becomes more noticeable when packing items—the 30L can carry more gear, like an extra sweater and towel. From the outside, the difference is subtle. In our experience, for day-long trips, choose the 30L backpack. For everyday use or if you have a smaller stature, go for the 18L backpack.
Here are two examples of people wearing both backpacks for real life backpack size comparison. The male model is 182 cm tall (6 ft), and the female model is 174 cm tall (5ft 9″).
