hard-shell

"Depending on the contaminant and its chemistry, if it is small enough to pass through the gills of the mussel, it has the potential to accumulate in their tissue or precipitate within the hard-shell structure."

And, owners get a zippered hard-shell case with room for the controller, a netted area for cables and a place to hold the accessory storage box.

Nerds, another Ferrara brand, has a hard-shell version.

She’s carrying a ginormous hard-shell cello case.

His hard-shell suitcase lay open on the bed.