Safety Box by Kreis Magic
Item Number: TA1206
A small brass box is displayed. There is a hole at the center, and a bolt is penetrated through the hole. The magician unscrews the bolt. Then, the box is handed to a spectator, and the lid is removed. There, a coin lies in the box.
Comes complete with small brass box, bolt & nuts, black sticker, and an illustrated instruction sheet that includes web links for additional performance and explanation video clips.