Bellows contact

The word originally meant a bellows. When a metal plate is processed into a terminal shape, the bent part is used as a contact point along with securing the spring by bending. It is mainly used when the roll surface (plate plane) side is used as a point of contact.
Improving the wiping effect requires more design know-how than extraction contacts. On the other hand, the large contact area reduces mechanical damage to the Mating side during mating.
Therefore, it is often used for interfaces with frequent Mating and I/O connectors. In addition, it is relatively easy to control the characteristic impedance of the contact area, and is often used in connectors that support high-speed transmission.