It has various modes. Beep Mode: It will make a sound when it detects metal. Vibration Mode: It will only vibrate when it detects a metal. High Sensitivity Mode: Detects even small metal objects like coin. Low Sensitivity Mode: Does not detect small objects. Detects only big metal objects like gun, knife. The Superscanna is a high performance Hand Held Metal Detector designed to meet the exact requirement of the security industry. Typical uses will include body search for offensive weapons in crowd control, airport and border security, checking parcels and letters for Metal objects and anywhere that hidden metal needs to be detected.