KZ-ZEX Electrostatic Dynamic In-Ear Sports Music Headphones, With Microphone, Without Microphone1. Electrostatic + moving coil hybrid dual unit technology. 2. Frequency response range: 20HZ 40KHZ 3. Plug Type: 3. 5mm 4. Pin type: 0. 75mm 5. Sensitivity: 103dB 6. Ergonomic design, comfortable and stable to wear. 7. Standard 2Pin interface, free combination. Specification: Package Weight One Package Weight 0. 09kgs 0. 21lb One Package Size 12cm * 9cm * 5cm 4. 72inch * 3. 54inch * 1. 97inch Qty per Carton 160 Carton Weight 15. 40kgs 33. 95lb Carton