The Inside is a subcomponent of String. An Inside usually contains up to 500 The Locks arranged in a random packing, but it's core contains an unknown state of matter, making Insides valuable for entities that can shrink or are already in quantum scale. It is somewhat unstable, and ejects 1 The Lock per hour.
The core of an Inside contains a mostly unknown state of matter, but we know it is a very dense soup of The Locks, akin to the quark-gluon matter inside a neutron star. Entities have tried to mine the cores of Insides before, but because of the 30% instability level they got teleported to a random Lock 30 seconds later and the whole thing failed.