The Undetectable Extension Charm - 4th-level Charm
Casting Time: 10 minutes
Range: Touch
Duration: Until dispelled

Transform an ordinary small bag/pouch into a Handy Haversack's central pouch, a backpack into a Bag of Holding, or a trunk’s internal capacity into a Bag of Holding with: 3 ft. long and 2 ft. wide opening; internal size of 6 ft. long, 4 ft. wide, and 4 ft. deep; 1000 pounds and 150 cubic ft. limits.