1Can adjust the phase angle and gain to eliminate unwanted signals before they get to the front end of the receiver. 2The builtin PTT control can maintain the stable and efficient connection status of the silencer during transmission. 3You can insert the QRM signal canceller into the feeder without any additional modification to the radio, very easy. 4Comes with dial and knob pointer, the QRM signal silencer allows for simple adjustment by rotating the the knob. 5The aluminium alloy shell is very sturdy and wearresistant, which also has great durability for a long service life. Item Type: QRM Eliminator Material: Aluminium Alloy Function: Eliminator Colour: Black Frequency Band: 1-30MHz HF 1 x QRM Eliminator 1 x Power Control Line There is a deviation of 0.51 mm between the dial and the knob pointer. Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.