An original Thayer masterpiece and extremely rare. Operates flawlessly. A free-standing miniature door (approximately 16" tall) is openly displayed and may be examined. As the performer summons spirits from the great beyond, the small door knocker begins to move....eventually rapping out answers to questions, etc. One rap for "yes"....two raps for "no"....three raps for "undecided" and so forth. The sound of the knocker is surprisingly loud and is easily heard from a good distance. The movement of the knocker is slight and almost imperceptible .. which adds to the eerie aspect of this unusual effect. Completely self-contained....no threads, pivoting panels or other similar methods. Condition: Excellent.