Eternity Perpetual Company

The Eternity Perpetual Company of planet Umbeka created products so longlasting that the company went out of business.

The company produced the everlasting power generators used in miniscopes, (TV: Carnival of Monsters) the Promethean Everlasting Matches used by the Doctor (PROSE: The Cabinet of Light) and the cosmic radiation batteries used in Super Lucky Romance Cameras. (PROSE: Borrowed Time) According to River Song, their batteries "last[ed] forever". (AUDIO: Peepshow)