I could have already passed through several of these security boxes. Or maybe not. None of theother humans I've encountered so far had any equipment that wasn't provided in the introduction, so these security boxes were probably not just scattered around.
I grabbed the wristbands from the vault, and as soon as I had them in my hands, the box slowly sank into the wooden platform. I could see that the box wasn't actually merging with the tree through its sphere; it was just... disappearing. When the last part of the box sank into the wood, all traces of the container vanished with it. Very similar to what happened with the giant pillar at the beginning of the tutorial.
I put on the wristbands, finding it relatively easy. The leather was strong, much sturdier than any other material I had seen with this kind of flexibility. I could probably even block swords and daggers with them, as their resistance to cutting seemed extraordinary.