Introduced in 1994, the Blancpain Léman Ultra Slim (Aqua Lung) reference 2100 features a ~38mm stainless steel case, screw-down crown, and 100m water resistance. Powered by Blancpain calibre 1150 automatic movement with ~100 hours of power reserve. Known for its clean design and thin profile, it set the tone for the entire Léman line.