Sealing

The seal (188) has at least one sealing element containing a ceramic material and being of annular shape with at least one contact surface for at least one of the components to be sealed (118,120), which is arranged at least partly essentially parallel to or inclined with respect to the ring axis of the seal. The searching element is subjected to compression during operation. Independent claims are also included for the following: a unit with two electrically conducting components to be sealed with respect to each other and a combined fuel cell block.