The Explorer II is equipped with an additional 24-hour display; a dedicated hand circles the dial in 24 hours rather than the usual 12, pointing to a fixed bezel with 24 hour graduations. This function enables the wearer to distinguish the hours of the day from the hours of the night, an essential feature for those who venture into environments where darkness reigns supreme - such as in the depths of caves, or where the sun never sets - like the polar regions in summer.