1LARGE RANGE COVERAGE: The filter covers 100 to 150 and is equipped with an omnidirectional antenna. The range refers to a circular area centered around the machine. 2POWER DESIGN: The single channel power of the anti monitor is 1W, with a total maximum total power of 4W, low power consumption, and safe use. 3EFFICIENT HEAT REMOVAL: For ventilation holes, as well as built in high efficiency heat dissipation fins and fans, to prevent local accumulation of heat in the filter. 4LONG LASTING BATTERY LIFE: Equipped with a built in lithium battery of 4Ah, this filter can be used anytime, anywhere, convenient to carry, and can last for a long time. 5WIDE APPLICATION: This anti listening device can be used in spaces with a radius of less than 15m, such as conference rooms, cars, computer rooms, and rooms. Item Type: Wifi Signal Filter Material: ABS Filter Range: 100 to 150 Battery: 1 x 4000mAh rechargeable lithium battery (shipped with built in battery) 1 x Wifi Signal Filter 1 x Power Adapter