Breaches

Breaches, also called wormholes or (transmatter) portals, is a portal in the multiverse which allows people to travel across the multiverse and between their universe. They are also explained as inter-dimensional space-time breach.

History
In 2020, multiversal breaches are no longer able to open on Earth-Prime as the physics of the Multiverse has been changed after the Crisis. However, it was proved by The Monitor in an erased timeline that breaches can be opened, but it cannot connect to the other Earths in the Multiverse. Additionally, transmatter portals can also be opened on the same earth. Breaches can open to various other 'planes of existence', such as the Speed Force via Temporal Wormholes, or singularities to the multiverse as a whole.