Rumor is this artifact was once the tool of a time Barron. It's a multi utility tool that can differentiate reality and mettle with simple mechanical or electrical devices.
To differentiate reality a roll is made against the level of the creature or device pulling subterfuge. The sonic spanner counts as 2 levels of resource. The exact nature of the subterfuge is not given, just that something is not as it seems.
As a tool the sonic spanner can lock and unlock simple locks. Can make security camera scramble for up to a minute and weapons misfire on their next use.
The sonic spanner is immune to all forms of attack and for all intensive purposes is invulnerable. It's also immune to all effects of time distortion and reality translations. So it always looks exactly the same no matter where or when it is encountered.