The Grav-Tether is a gadget created by Pollyx Industries in Into the Nexus used by Ratchet. It is fired between two grav targets to create a purple grav-stream between them, in which the user can float between the beams in a specific direction. This allows Ratchet to reach otherwise inaccessible areas.
The Grav-Tether is used by holding , aiming at a grav target and then pressing . Firing it at two opposing grav targets creates a grav-stream. Two grav-streams can potentially cross over, allowing Ratchet to switch to a new grav-stream and access a new path. To exit the grav-stream, the player must press .
When in a grav-stream, a specific soundtrack known as "Gravtether Jayn" plays.