DID 520ERS2: The letters ER stand for "Exclusive Racing" with DID and thus unambiguously determine the field of application of the 520ERS2. With its very low weight, it is suitable for both road and off-road racing. For those who want to get the last out of their machine. - specially developed for racing - very low weight Gold-colored outer pockets, gold-colored inner pockets (G & G Gold and Gold).