1、The QRM canceller can be inserted into the feeder of the antenna without any other modifications to the radio. 2、Built-in PTT control to keep the canceller connected during transmission. Phase adjustable, two gains adjustable, easy to adjust by the rotation knob. 3、An additional auxiliary receiving antenna is required, such as a 2m antenna or only a few meters of wires in a shed. The two antennas receive unwanted signals, resulting in different phases. 4、The QRM eliminator allows adjustment of the phase angle and amplification to cancel unwanted signals before they reach the receiver front end. 5、Aluminum alloy casing, sturdy, firm and wear resistant, with high strength and great durability. QRM canceller can be inserted into the feeder of the antenna without any other modifications to the radio. With aluminum alloy casing, built-in PTT control, adjustable phase and two gains, it's convenient and High quality to use. It is based on a completely innovative concept and cannot be compared with the normal "silencer" performance. Features: The QRM canceller can be inserted into the feeder of the antenna without any other modifications to the radio. Built-in PTT control to keep the canceller connected during transmission. Phase adjustable, two gains adjustable, easy to adjust by the rotation knob. An additional auxiliary receiving antenna is required, such as a 2m antenna or only a few meters of wires in a shed. The two antennas receive unwanted signals, resulting in different phases. The QRM eliminator allows adjustment of the phase angle and amplification to cancel unwanted signals before they reach the receiver front end. Aluminum alloy casing, sturdy, firm and wear resistant, with high strength and great durability. Note:Size and color may be slightly different due to manual measurement and different light conditions. Thanks for understanding. Specifications: Color: Black Material: Aluminum Alloy Item Size: 133 * 122 * 44mm / 5.24 * 4.80 * 1.73in Item Weight: 370g / 13.03oz Package Size: 20 * 13.2 * 5.7cm / 7.87 * 5.20 * 2.24in Package Weight: 427g / 15.05oz Package List: 1 * QRM Eliminator 1 * Cable 1 * QRM Eliminator 1 * Cable