MHD MK-4 Universal In-ear Headphone with Microphone for Tablet Cellphone  Features: Adjust volume and switch songs freely. Complete aluminum sound cavity. Built-in microphone、 volume control、 next\/previous song switching. S.P.L. at 1kHz (dB) Distortion rate 1 (%) Speaker diameter 10 (Φmm) Weight:100g Specifications:          General Specification             Brand Name       MHD             Model Model        MK-4             Color        Black             Cable Length        1.2m             Wearing Type        In-ear           Technical Parameters            Wired Control         Yes             Driver Unit        3.5mm             Receive Sensitivity        116dB±2dB             Impedance        16Ω             Frequency Response        20-20kHz    Package  Included:                   1 X MHD MK-4 Earphone