9mm in-ear earphones with phone adapter. Noise-isolating earphones with contoured eartip design to reduce exterior noise. Changeable eartips in 3 sizes for a custom fit. Includes adapter for 2.5mm cellphone jacks. Gold-plated 3.5mm jack for maximum signal transfer and sound. Sensitivity is 93 dB. Frequency response is 20 Hz - 20 kHz. Cable length is 3.9".