- Limited Series -
This term refers to the fact that a limited number of watches have been made in a particular series.
- Lugs -
Part of a watch where the band or bracelet is fastened.
- Luminous Hands -
These hands are usually adorned with a material that allows them to glow in the dark. Traditionally, materials like tritium were used to make the hands of a watch luminous. Zinc compounds will react with the tritium, which is what causes the hands of a watch to glow. Most of the modern watches with this feature will use Superluminova. This material is non-radioactive and much safer to use then tritium. The pigments, known as lume, are activated by light. Once the light is taken away, these particles glow to light up the hands of the watch.
- Luminous Numerals -
These numerals are coated with a material to make them glow in darker areas. Tritium was used in the past to create this luminous appearance, but newer watches use Superluminova. The pigments or lumes in this substance are charged by light and then glow when the light is removed.