A Fancy case

you open the cardboard box to be met with a fancy wooden case and if you're mistaken, is made of expensive mahogany and are those gold plated hinges ?, "Man..., if they ever found out who misdelivered something this expensive, they will get their ass kicked to the moon, or sued into oblivion...", you commented as you lift it up to enact the 'Finders Keepers law' and put it on the coffee table to open later and saw a note inside with the case.

'User is recommended to only use one item and the other one to be kept in the case or used with precaution', what could be inside this fancy case ?.