PyleSport Metal Detector - Waterproof Search Coil Extendable Locating Arm 41.3&rdquo; to 51.2&rdquo; w/Adjustable Sensitivity and Headphone Jack - Built-in Speaker w/Detection Ping Alert Battery Operated PHMD53 ADJUSTABLE SENSITIVITY: Metal is detected once the coil approaches it, with an included ping detection alert. Adjustable sensitivity at &gt;13cm. It also has ten level adjustable discrimination and sensitivity controls. PINPOINTER FUNCTION: The pinpointer metal locator function allows you to hone in on your find. It effectively locates precious metals and treasures buried underground like gold, silver, iron, coins, jewelry and more. WATERPROOF SEARCH COIL: The coil is waterproof and submersible at 8.0 inch. It helps you search for lost metal items at the bottom of a shallow pool or stream. ADJUSTABLE STEM: The adjustable locating arm can be extended from 41.3'' to 51.2''. It has a comfortable holder support and grip that makes sure the detector is easy to handle at any level of experience. BUILT-IN SPEAKER: Built-in speaker with detection 'ping' alerts. It will immediately beep to alert you when it detects metal. Also it has automatic ground balance for accuracy and reliability. Battery operated with headphone jack 3.5mm.