air bladder
noun1
An internal organ that fish use to control their buoyancy, allowing them to maintain or change depth by changing their density.
2
A type of packing material that consists of an airtight bag full of air, used to cushion fragile items.
- The company used to be notorious for excessive packaging, and social media grew littered with examples: three pairs of socks wrapped in puffy air bladders[…]2019 November 21, Samanth Subramanian, “How our home delivery habit reshaped the world”, in The Guardian: