Gerudo Token

In Ocarina of Time, the Gerudo's Membership Card, or Gerudo Token, allows Link to pass through Gerudo Fortress without being thrown in prison.

Location and Uses
Link obtains this from Nabooru's Second-in-Command after sneaking past all of the Gerudo Guards and freeing the four carpenters, Sabooro, Shiro, Jiro, and Ichiro. This is vital when journeying to the Spirit Temple for the first time, as Link needs the card to have the gate opened without being caught, as well as being able to walk around freely and being able to participate in the horse challenge and training grounds. Though the Gerudo do not usually grant membership to men, Link's apparent skill earns their respect, and so he is unceremoniously admitted into their exclusive group.