Greybox
Greyboxes were magical storage devices that could create localized portals to The Grey Plane. They were invented by Theodore Perry in 275 DHT and served as accessible yet expensive extraplanar storage devices, typically used to "compress" large quantities of material or goods into a small space. Unlike other Grey Plane storage vessels, greyboxes were uniquely able to be reused even after taking out material.
Larger greyboxes held no intrinsic value other than opening larger portals to store larger objects within.