The magician shows a box with two large windows on two sides. He opens the front door to show that the box is empty. Now he sticks his arm lengthwise through the box - his arm almost completely fills the box.
He closes the front door and opens the lid at the top of the box.
Now he apparently ignites his arm through the hatch - everything burns - until he closes the hatch afterwards and pulls his arm out of the box again undamaged.
Dimensions 21x13x13 cm