1、Impulse Induction (PI):This technology allows detection in salt water on the beach or in any type of soil, including grass, mud, dust, sand, black sand, and water. 2、High Sensitivity:The metal detector has maximum sensitivity, which can improve the detection of gold nuggets and other small targets. 3、Good Waterproof: The handheld metal scanner is completely waterproof and can be submerged up to 100 feet underwater, making it best for underwater treasure hunting. 4、Hint Function: When a target is located, the handheld metal detector emits vibration pulses and a strong flash of light to help you find the metal more easily. 5、Easy to Install Use: The metal scanner is easy to use, just install the battery and turn it on with the coil facing up for a few seconds. A flashing LED light indicates that the device is turned on. Item Type: Underwater Metal Detector Material: ABS Detection Method: Impulse Induction(PI) Detection Object: All Metals (Iron, Aluminum Ring, Small Aluminum Products, Coins, Gold, Copper, Silver) Alarm Mode: Vibration and LED Light Waterproof Rating: IP68 Sensitivity: 25 Cent Coin:Approx. 10mm / 0.4in One Dollar Coin:Approx. 15mm / 0.6in Battery: 1 x 6F22 9V Battery (Not Included) Item Size:Approx. 440 x 105 x 112mm / 17.3 x 4.1 x 4.4in Packing Size:Approx. 45 x 10 x 10cm / 17.7 x 3.9 x 3.9in Package Weight:Approx. 580g / 20.4oz Weight:Approx. 300g / 10.6oz 1 x Underwater Metal Detector 1 x User Manual