Once they got seated for lunch, Cain decided it was time to check out the jewels that they bought from the first pavilion.
The matched jade items give him the feeling that they belong together, so Cain is leaving them for last and instead starts with the plain black bracelets. As he suspected, they are mana storage devices and fully charged, but the inspection reveals that they are usable only by a demon. Each of them can hold ten thousand mana, an enormous amount for the average transfer.
Honestly, it feels too good to be true, and Cain knows item descriptions can be altered, so he calls a Record Keeper into [Greater Merger] with him. The demon has the ability to see through all sorts of enchantments, so Cain takes a closer look, using the Demons sight.