Cryo B was a cryogenic stasis chamber on board the Halcyon-class light cruiser UNSC Pillar of Autumn. John-117 was placed here during the trip from Reach to Halo. Following standard UNSC procedure, Keyes jettisoned most of the Cryo-chambers upon arrival in-system and there were only nine of them left when they found Installation 04. Cryo B has two sections, separated by several corridors at the bottom, and the Main terminal at the top. Each section holds 28 cryo-tubes.