A Magnetic Eyeliner & Eyelashes 3-in-1 System is a simplified alternative to traditional false lashes. Instead of messy glue, you apply a magnetic eyeliner that contains iron oxides. The lashes themselves have tiny magnets embedded in the band.

When you place the lash strip against the dried magnetic liner, the magnets attract and "click" into place, holding the lashes securely. The "3-in-1" typically refers to the core components of the system: the magnetic eyeliner, the top lashes, and often a separate set of lower lashes or a specific tool.