Hi all.
Sorry about my lack of German. I'm the owner at Deru.
In answer to the questions:
Weight - 260g with 43cm x26cm x0.5cm foam back plate. This weighs 30g
47cm (77cm unclosed) x 15cm x 28cm
Quoted at 18L, but has 2x mesh side pockets and x1 large mesh front pocket - should be pretty close to 25L.
Construction is fully taped.
Made in Japan.
Cost is €455
We ship worldwide.