The box contains information pertaining to the people of Earth, extending a hand of friendship. As an additional feature, Captain Samantha Carter installed Iridium in the boxes. The distinct nuclear signature of iridium could be detected in the event that a Sagan Box impacted the iris, thus enabling the SGC to determine if it was safe to open the iris or follow-up off-world. It became standard procedure for SG teams to give Sagan Institute Boxes to the peoples they encountered if first contact went well.