A Bag of Holding is a small sack that allows an OASIS character to carry more than they could carry otherwise. It appears to be a common cloth sack approximately 2 feet by 4 feet in size. The bag of holding opens into a non-dimensional space: Its inside is larger than its outside dimensions. Regardless of what is put into the bag, it weighs a fixed amount. This weight, and the limits in weight and volume of the bag's contents, depend on the bag's type.
The bag was found by Parzival in the Tomb of Horrors.
The bag increases the default quantity of items an OASIS avatar can carry on their person at any given time.