There are two styles of bellows type air springs available; the crimped design and the sleeve type.
With the crimped design bellows type air springs, the end retainers are permanently attached by mechanically crimping the retainer around the built-in bead wire of the flexible member.
Sleeve type bellows offer similar characteristics to the crimped design bellows, but, as with the sleeve type rolling lobe the flexible member is constructed without internally moulded bead wires. The end retainers are permanently attached by pinching the flexible member between the end retainers and external crimp rings which are then swaged to the proper diameter.
Sleeve type bellows offer the lowest force to compress of any type of air spring.