Roughly conical in shape, they seemed to be able to hold one or two individuals per pod. Each individual pod had a large impulse engine on its aft section.
In 2375, when one such vessel's core started to breach, the crew abandoned ship in 37 escape pods. The pods then sent an automated distress call, picked up by the USS Voyager. When they arrived, the pods were heavily contaminated with theta radiation and only two Malon survived. (VOY: "Juggernaut")