Whilst Oa was the headquarters of the reborn Green Lantern Corps, the resurrected Guardians of the Universe had spread their 7200 Green Lanterns across the 3600 sectors of known space. In order for their agents to better serve in their assigned duties, special structures were created known as Sector Houses that were shaped as Green Lantern Power Battery's which were used to hold captives in custody in order to brought to Oa for confinement in a Sciencell. In addition to this purpose, they served as recreational centers as well as meeting places for Green Lanterns of neighboring sectors. A warning system within these spaceborne buildings notified the Green Lantern Power Ring wearers of any troubles within the sector.