Features: The antenna is suitable for indoor shortwave reception, enjoy the broadcast from this moment on shortwave, cross-regional (national) listening. With 3-30MHz frequency coverage and excellent performance. The antenna is made of stainless steel, which is light and durable. The power control box contains a 1000mAh lithium battery, which has been charged to Type-C and the light will automatically change color when fully charged. The radio loop antenna is compact,you can install easily on balconies, rooftops, and other places, featuring compact size. Specifications: Frequency Range:SW2.30-30MHz,MW552-1710KHz(Need MW Port) Impedance:50ohm Gain:20dbi Ring Diameter:Approx.20cm/7.87in Control Case:Approx.10.5x6.5x2.6cm/4.13x2.56x1.02in Charging Port:Type-C(Light is red when charging,green when full) Material:Stainless Steel,ABS Note: Please allow 1mm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1X Stainless Steel Ring 1X Control for Case(built in 18350 battery) 1X 1m RG174 Feeder Cable (BNC+3.5mm)