They are excellent for absorbing vibration and multi-directional movement, especially in high-pressure or nuclear environments.
Because "bellows" can refer to several different things, here are reviews for the most common interpretations: the industrial component, the photographic accessory, and the horror video game. bellows
In engineering, bellows are convoluted shells that compress or extend to handle pressure or thermal expansion in piping systems. the photographic accessory
Multi-ply designs offer a better fatigue life than single-ply versions. bellows