[DIY Welding Exercise]: Metal detector DIY kit, you need to weld and assemble it by yourself, providing an engaging way to learn about electronics and circuit board assembly. It can not only exercise hands-on ability, but also improve electronic production skills, suitable for electronic enthusiasts and students. [Dual Alarm System]: When the detector is close to the metal, the buzzer and LED light alarm at the same time, providing both visual and auditory prompts for more accurate and convenient detection. [Adjustable Alarm Threshold]: By rotating the potentiometer, the alarm threshold can be adjusted according to your needs to make the device more sensitive and meet different detection needs. [Portable Design]: The metal detector is compact, , and easy to carry, suitable for use in environments, such as games and entertainment, checks, and so on. [Learn Knowledge & Cultivate Thinking]: By assembling and using the metal detector by yourself, you can cultivate interest in electronic and physical knowledge and stimulate innovative thinking. Perfect for beginners looking to explore the fundamentals of electronic and circuit design. Specifications: Name: Metal Detector DIY Kit Battery: 2 * CR2032 button batteries (not included) Working current: 23mA (under normal alarm condition) Static working current: 3.7mA (without alarm) Working voltage: 3-5V Maximum detection ranges: 30-50mm LED flashing alarm: support Adjust the alarm threshold: Support Buzzer sound alarm: Support Power switch: Support Power indicator: Support Colour:black Material:PCB+Components The actual product may have slight color difference or difference, which not affect the use (This is just a DIY kit, you need to solder it yourself) Package Contents: 1 * Metal Detector Electronic DIY Kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.