China Mystery Square Circle by Mr. Magic - Trick
A great and magical production device! Remove a tube from an empty box (which is transparent on the front side) and show that the tube is empty as well. Place the tube back inside the box, and produce an item (e.g., large scarf, small plush bunny, etc.). You can remove the tube, show it and the box empty once again, place the tube back inside, and produce even more items! Very magical and gets great audience reactions!