The Kena Upanishad also called Talavakara Upanishad is one of the earlier main, i.e. Primary 'or' Mukhya Upanishads. It is associated with the Sama Veda.
Though it is a very short text, this classic Vedic scripture is time immemorial and is meant to be read, re-read and studied to understand the true nature of our consciousness and existence. In addition to the text of Kena Upanishad, this book contains an introduction to the very concept of Upanishads, lists out the main upanishads and also provides an introduction to the Kena Upanishad.