... airports, industrial zones, government buildings, schools, hospitals, etc. hand-held metal detector MD-200 Features:1. Operating frequency:2. Weight: 272g3 ... respectively11.Highly sensitive, detect ferrous and non-ferrous and stainless steel weapons12. Sound and light alarm simultaneously13. Alkaline cell (7V-9V ... ): 40mm h) Lead brick (1g): 30mm High Sensitivity Hand-held Metal Detector MD-200