The Streetwise Handheld Metal Detector is designed for use by law-enforcement officers and security personnel to quickly detect even the smallest metal weapons. It is sensitive enough to detect a handgun or knife from six inches away. With its large detection area, you can do a fast yet thorough scan. The lightweight design and comfortable handle make it easy to use for long periods of time. With its adjustable sensitivity, this metal detector is ideal for use in airports, schools, prisons, sporting events, etc. It has both audible and vibration alerts. The vibration alert is ideal for loud environments such as concerts or nightclubs or quiet environments like an office building or library. It is powered by either a standard or rechargeable 9-volt battery. Features a low battery indicator light so you will know when it is time to replace the battery.