Reasons for using this high pass filter (HPF): The electromagnetic environment in cities nowadays is too poor. The high-power medium wave radio stations (with power levels ranging from 50-500KW) and high-power short wave radio stations (100-1000W) in cities can cause immeasurable interference to our communication due to their scattered broadcast radiation. If you live near a medium wave radio station or use a low-grade radio station, I believe everyone has experienced poor signal or the sound of medium wave radio stations covering the entire frequency range. Another common situation is that if the cable TV cables in your community are aging or the installation quality is not high, or if non professionals have tampered with the cable, I believe everyone has had the experience of being a "broadcaster" before. Therefore, it is necessary to install a low-pass filter for shortwave. The most serious situation is the interference from current electric vehicle chargers and various switch mode power supplies. The of most switch mode power supplies is below 500KHz, and this interference be very serious. 1. Model: HPF-1.0M-100WN 2. Frequency range: 1.0MHz (other frequencies can be customized) 3. In band attenuation: 0.5db 4. Power: 100W (SSB CW AM FM) Higher power can be customized 5. Input impedance: 50 ohms, output impedance: 50 ohms 6. Standing wave: less than 1.5 7. Interface: L16-F (N seats) (other interfaces can be customized) 8. External dimensions: 140 x 53 x 38mm (mounting hole size: 110 x 34mm) 9. Net weight: 216 grams Color: As Shown Material: Metal Package Contents: 1 * Wave Filter 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.