Use domain:
The Body Scanner/ Metal Detector is ideal for using at airports, industrial sites, government buildings, schools, hospitals, conferences, sport events, and anywhere you need security. It's sensitive enough to detect metal object the size of a 25 cent piece. It sounds a high-pitched tone whenever it detects metal- a longer tone for larger objects, and a shorter one for smaller objects. You can use rechargeable nickel-cadmium battery for power, and recharge it in the Body Scanner.

Specification:
Sensitivity:
1. A25 cent coin(USD)---2.5 inch(0.6 inch");
2. Iron pipe-tube in 20mm---4 inch(1.2 inch").
Temperature environment: -10-- +50;
Operating Current: <6mA;
Weight: 430g;
Dimension: 420*80*40 mm;
Power: 6F22 9V*1 (low bettery alert);
Operating Frequency: 13 KHz;
Tuning: Automatic;
Alert: Audio & LED Light

*With reduced sensitivity by pressing and holding Desensitize Button.