Negative Space Unit

So here's the idea; you've got this pill shaped device which splits in two. When active, pulling apart the pieces creates an energy chord infinite in length. The chord floats in mid air which allows flexibility of window shape and size. When the lines cross, an inter-dimensional window is created allowing the storage of or secrecy of any object.

*Side note - The dimension the unit connects to is always the same, very close to our own, but there are no objects or light there, only ground and near infinite space.