From Guild Wars 2 Wiki
This device looks like it does something, but you don't know how to turn it on.
— In-game description
- Interact with the object marked "???" at the bottom of Gillscale Pond after jumping through a Class I Magic Rift.
- In order to jump through a rift, someone has to open one. Try to get someone who already has a stabilizer to open one for you.
- At times when the map is lightly populated, this can be difficult. However, if you have a character who already has one, you can try logging in with that character. Create a rift, and then log out immediately. There may be enough time to log in with your other character and jump through the rift created by the character who had a stabilizer.