This is a rare Pokéwalker exclusive silicone cover, Lugia.
The package is in long-term storage in a warehouse and has some scuffing, sagging, and stains on it, but there is no noticeable damage that could lead to breakage.
The unopened item is quite rare, so if you have been looking for one, why not?
Please note that this is a cover only, and the main body of Pocketwalker is not included.
Please note that this is a very old item.