Normal impedance:300phm. Jack plug :2 pin(two mono). Frequency response:20Hz-20000Hz. Charactaristic SPL:100db@1KHZ 1. Style: Mini in-ear earphone, clip-on headphone, over-head headphone, noise cancelling headphone 2. Impendance: 300phms3. Magnet: Neodimium, Ferrite4. Spearker: 15mm, 27mm, 30mm, 40mm5. Pin: single pin, double pinCompany instructionJIANGYIN LIKN INDUSTRY CO.,LTD is a special ...