Bolder's ring, more commonly known simply as the ring ( or Xeelee Ring ), is a highly advanced xeelee structure and one of their greatest achievements.
The ring has a diameter of 10 million lightyears (100 times that of the milky way galaxy) and is made of cosmic superstring. The Xeelee constructed it over the course of billions of years during which they converted the mass of thousands of galaxies into the rings superstring. The ring spins near the speed of light, which combined with its mass, causes the creation of a naked singularity at it's center. The enormous mass of the ring locally counteracts the expansion of the universe.
21st century humanity was aware of the gravitational anomaly created by the ring and dubbed it The Great Attractor. Upon discovery of the ring itself, humanity mistakingly assumed it to be a weapon, while instead it is a portal used to escape the universe.