64 Audio U6t, Universal-Fit In-Ear Headphones, With 6 Balanced-Amature drivers (1 tia BA high frequency driver, 1 BA mid-high frequency driver, 2 BA midrange drivers, 2 BA low frequency drivers), 4-Way passive crossover, Modular Apex module (m15, m20) for an effortless sound experience, Ergonomic aluminium enclosure, LID technology preserves sound character independent of playback device, Frequency response: 10 - 20000 Hz, Sensitivity: 108 dB/mW @ 1 kHz@+@+*Contents of delivery:*@+@+, Leather case, TrueFidelity foam earpieces (S,M,L), Silicone earpieces (S,M,L), SpinFit ear molds (S,M,L), Black premium cable with 3.5 mm jack plug, 2 Apex modules (M15, M20)