# サイリュウム

**サイリュウム** – *sairyumu*. Named after Cyalume, an actual brand. Often confused with LED light sticks and has become synonymous with them, but they actually refer to **chemical light sticks**, **chemlights,** or **glow sticks**. These are intense sources of light that with the most common varieties only lasting around one and a half minutes (depending on the type as some are more intense and last only a handful of seconds before it quickly starts to fade) and they are usually activated during key parts of a song.

There’s a lot to add to this that goes beyond the scope of this glossary but suffice to say, people either love it or hate it but they definitely see it.