The lamellae of a gecko are the thin strips under their toes that allow them to climb vertical surfaces. Each lamella is covered in tiny microscopic structures that can grip even the slightest imperfection in a surface, even glass.
This "super grip" is often attributed to the aid of a van der Waals force, which is an attraction between the molecules of the gecko's lamellae and the climbing surface. Because of this, a gecko can support it's weight on a vertical surface with even just one toe. This particular foot belongs to Lybbi, a ringed wall gecko, Tarentola annularis.