1. GA-490 High-Performance Active Loop Antenna Is An Antenna With Excellent Receiving Performance. 2. When It Is Used For Ordinary Radio Reception, The Shortwave Effect Is Very Obvious. 3. When Using Frequency Modulation, It Can Be Used As A Passive Antenna, And Its Effect Is Better. 4. When Used For Sdr/Malachite Radio Reception, It Can Also Be Used As A Full-Band Receiving Antenna. It Has Good Reception Effects On Fm, Medium Wave, Short Wave And Aviation Bands. It Is Recommended To Install It Outdoors, From Buildings Or Other Obstructions. 5. It Uses High-Quality Shielded RG174 Feeder And High-Quality Connectors. Therefore, It Can Be Used In Different Machines, Using Appropriate Adapters. The Antenna Can Be Installed In Open Spaces Such As Balconies And Outdoors. It'S Your Inefficient Outdoor Receiving Antenna. Model: GA-490 Working Frequency: 100KHz-179MHz (High-Performance Receiving Frequency 100KHz-30MHz) Power Supply: Built-In 18650 Lithium Battery Charging Circuit: With Battery Protection/Type-C Charging/5v-1a Gain: 20DB (Max) Impedance: 50 Ring Size: 50cm/19.7inch Tuning : No Tuning Application Scenarios: Indoor (Hanging On Balcony)/Outdoor Working Voltage: 9-12V Built-In Battery: 2600mAh (18650 Lithium Battery) Note:Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Will Not Affect The Use type:20M Colour:As Shown Material:plastic Package Contents: 1 x Outdoor Antenna Box 1 x Indoor Power Box 1 x Connection Cable 1 x Bnc Connector 1 x Charging Cable 2 x Adapter (Sma And F Connector) 2 x Support Rod 1 x Ring 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.