A portable hole is a circle of magical cloth spun from the webs of a phase spider interwoven with strands of ether and beams of Astral Plane luminaries. 

When opened fully, a portable hole is 6-ft in diameter, but it can be folded as small as a pocket handkerchief. 

When spread upon any surface, it causes an extra-dimensional hole 10-ft deep to come into being. 

This hole can be "picked up" from inside or out by simply taking hold of the edges of the magical cloth and folding it up. 

Either way, the entrance disappears, but anything inside the "hole" remains. 

The only oxygen in the "hole" is that allowed by creation of the space, so creatures requiring the gas cannot remain inside for more than a turn or so without opening the space again by means of the magical cloth. 

The cloth does not accumulate weight even if its hole is filled with gold, for example. 

Each portable hole opens on its own particular non-dimensional space. 

If a bag of holding is placed within a portable hole, a rift to the Astral Plane is torn in the space, and the bag and the cloth are sucked into the void and forever lost. If a portable hole is placed within a bag of holding, it opens a gate to another plane, and the 'hole, bag' and any creatures within a 10-ft radius are drawn to the plane, the portable hole and bag of holding being destroyed in the process.