Complex sentence: The temperature and humidity controlled-case is filled with argon (99.5%) and oxygen (0.5%) to prevent chemical changes, the Shroud itself is kept on an aluminum support sliding on runners and stored flat within the case.
Split into simpler sentences: The temperature and humidity controlled-case is filled with argon (99.5%) and oxygen (0.5%) to prevent chemical changes. The Shroud itself is kept on an aluminum support sliding on runners and stored flat within the case.