Product desciption: The malachite radio has a pre-filter to make up for the design error of the malachite radio with an all-metal aluminum shell not adding a pre-filter and reduce interference in medium-wave, short-wave and FM broadcasts. The filters are divided into four groups. 1. Size: 48.5x45x18mm (excluding connectors) 2. Net weight: 51g 3. Anti-static bag packaging 4. Impedance 50 ohms 5. Connector: SMA female Colour: Black Material: Aluminum Package Contents: 1*Malachite Radio Pre-Filter(Due to different product batches, the appearance may vary, which does not affect the use) Only 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.