MFJ Communication Headphones are perfect for amateur radio and shortwave radio listening. All modes: SSB, FM, AM, data and CW. Superb padded headband and ear cushions makes listening comfortable. You';ll forget they are even on as you listen to stations all over the world. High performance driver unit produces enhanced sound. Signals never sounded so clear. Free 1/4 inch phono adaptor, gold plated plug. 9 foot cord. Weighs just 8 ounces. MFJ-392B handles 450 mW and has a frequency response of 20-20,000 Hz. Impedance is 32 Ohms, sensitivity is 102 dB/mW. Works in stereo mode with 3.5 mm plug. Works in mono mode with 1/4 inch phone adapter. These are used items, second hand, have cosmetic defects.