This product is a versatile utility prop used for vanishing and re-appearing many different items.
The magician presents a box with a window. The box has a cylinder in it. The cylinder can be clearly be seen through the window in the box. The magician pulls the cylinder out of the box and shows the audience that there is clearly nothing inside the cylinder. The magician puts the cylinder down on the table. Then he continues to pull many different items out of the box that is clearly empty through the window.