The Key to Time is DVD boxed set released by 2 entertain that contains all six stories of Season 16 and its arc The Key to Time. These are: The Ribos Operation, The Pirate Planet, The Stones of Blood, The Androids of Tara, The Power of Kroll and The Armageddon Factor.
The complete running time for all six serials in the arc is 633 minutes.
The Key to Time is available on DVD in North America it was released on region 2 (Europe) DVD on 24 September 2007. It was originally offered as a limited edition product within the UK market before being re-released.