High level clarketech device. Basically a box from 0.5 to 1 meter on a side that is larger on the inside than on the outside. May employ a basement universe or space-time folding (no S-level below the creating intelligence knows for sure). A Finity Box may be as much as five times larger on the inside than on the outside and no amount of mass put inside it causes any perceptible change to the mass or inertia of the box itself.
So far some 2048 Finity Boxes have been found, all within a 5 LY radius of the brown dwarf Grupna Red, and between the years 5221 to 5279 (late ComEmp period). None have been found since, despite repeated searches. Nor has any ISO been observed in the vicinity.
Since their discovery, several Finity Boxes have been stolen, 2 have been destroyed, one spontaneously disassembled when probed with an exploratory nanowormhole, and 12 are used in space-time hyperdimensional research. The rest reside in private collections or archailect museums throughout the galaxy.