I bought the Nest backpack(with the 10L pouch) back in July 22 and it's disappointing. The quality of the of the material is way below what you would expect for the price. I used it only as an everyday bag to go to work and it already started to tear off on the bottom compartiment (the one with the water resistant pouch). it also begins to deteriorate at the laptop pocket zio protection and other places. The elastic mesh on the outside is almost not elastic at all which makes its original use extremely difficult. you could probably put a bike helmet only if the bag is empty which is useless then. Well to resume, the idea was nice but the quality is not there. if it was like 60€ ok but for a bag at around 150€ it's really impossible to recommend it when it has already started to detariorate after 3 months of casual use