A cube contained in a wooden container, seemingly penetrates through a metal plate . . . like a ghost through a closed door !

An incredible penetration effect, from decades ago when mechanical props were works of real magic.

Performer displays a wooden tube with cutouts, so spectators can see right through the tube. A metal plate passes through slots in the middle of the tube, dividing it in half, so nothing can go through. The Performer next displays a large Cube ( filling the entire upper half of the tube ) and drops it into the tube. As expected it rests on the plate in the upper half, fully visible through the cutouts. Yet with a simple magic pass, and no cover, the Cube is caused to penetrate visibly through the metal plate, now resting in the bottom half of the tube.

A nicely designed effect, well constructed in wood and metal and very durable, should last for many many performances.