Features:1. Convenience: The QRM canceller is inserted from the into the feeder of the antenna without any other modification to the radio.2.PPT Control: has a built-in PTT control to keep the canceller connected during transmission. However, an additional auxiliary receiving antenna is required, such as a 2m antenna or only a few meters of wire in the shed. The two antennas receive unwanted signals, resulting in different phases.3. Adjustable: Allows adjustment of the phase angle and amplification to eliminate unwanted signals before reaching the front end of the receiver! It is based on a completely innovative concept and cannot be compared with normal "" performance.4. Material: The material is excellent, the shell material is aluminum shell, and the front and rear baffles are: epoxy glass fiber board FR4.Specification:Connections: Main Antenna, Auxiliary Antenna and 3xBNC forRCA jacks for PTT are: 5.5x2.1mmRequired power supply: 13.8V/150mASize: about 124x113x51mm/4.88x4.45x2.01inchcolor: Blackmaterial: metalNotice:0.5-1mm deviation between dial and knob pointerPackage Contents:1 x QRM Eliminator1 x PTT Wire1 x FM Rod Antenna1 Cord3 x F Adapter UHF/SL16-SMAOnly 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.