Rubber bellows have versatile functions as “dust boots” or seals, used to seal out dust and other light-duty environmental factors while allowing a specific stroke or predetermined range of motion. They are quite common in industrial and automotive applications.
Similar to rubber bellows are products that function as tubing, ducting, or even as an expansion joint. However, bellows are mainly employed as a protective cover.
Depending on the manufacturing process, molded bellows may have an extended resting position (convolutions are extended in resting position). Think of a convoluted drainage pipe for example.