Sleuth BallEffect: A refined wooden box is opened to reveal five resin balls in sequential arrangement four white and one black. The magician then turns his back or even blinds his eyes. Each of five audience members takes a ball, and the magician already knows who has taken the black ball. Features: Long press on off setting. Suitable for stage and hall sizes. Dual display with vibration and light. Physical induction trigger, with one hundred percent accuracy.