Fangrui Product Details Features: With The Lcd Display Screen, So You Can See The Data More Clearly, Give You A Better Using Experience. With 3.5mm Audio Interface Input And 3.5mm Audio Interface Output, You Can Connect With The Speakers Or Power Amplifiers To Use. Dnr Is The Noise Reduction Level, A Total Of 10 Levels. Flt Is The Digital Filter With A Total Of 10 Grades, Which Are 200hz Low Pass, 500hz Low Pass, 700hz Low Pass, 1khz Low Pass, 1.8khz Low Pass, 2khz Low Pass, 2.4khz Low Pass, 3.5khz Low Pass, 6khz Low Through, Through. Filter And Noise Reducer Can Be Used Together Freely, The Button Setting Is Simple, Which Is Easy To Use. Using The Micro-usb Input To Supp- Power, With The Built In Speakers, Or Connect With The External Speaker Or Power Amplifier.suitable For Old Radio Stations Without Noise Reduction Function. All You Need To Do Is Output The Audio From The Radio Station To The Machine, Which Is Simple. Specifications: Material: Aluminum Alloy Colour: Black Package Contents: 1 X Noise Reducer 1 X Usb Cable