Made of good plastic shell, safe and eco-friendly, sturdy to use. Having an excellent workmanship: Beautiful appearance, streamline design, light weight, compact size, high sensitivity, bringing much convenience for you to operate. Detecting distance range is 3-20m /9.8-65.6ft, the sensitivity of this metal detector will change according to the detected object's size, volume, density and environment etc. factors. It has two types of optional alarm mode: mode (buzzer and red indication light) and vibrational mode (vibration and red indication light). Lower power consumption：It only need 1 x 9V6F22battery. AndIt also has alarm indication, yellow led (having detected object), flashing green led (machine starts to work), flashing red led (lower power)