Rules:

*You can teleport into and out of it at will

*It has a couple of plug sockets and can connect to internet from the region you teleported in from

*You can take objects and people with you

*As already stated, it is 3m^3. The walls are plain plaster with a light in the middle of the ceiling. The pocket dimension is topologically toroidal, so if there weren’t walls and a ceiling/floor (which you can actually destroy) you would loop if you went more than 3m in any direction. Gravity, then, is artificial and can be altered to anywhere from 0 to 2g from a dial on the wall.