First custom earphone in the world with a single 14mm dynamic driver couples with advanced frequency suppression technology (FST). Frequency Response: 10-20000 Hz Impedance：16ohms（including cable） Sensitivity (at 1kHz)：116dB spl (1mW) Important: Due to the size of the driver, people with small ears may not be able to fit. We would need your ear impressions to check for sizes...
Brain Acid in-ear buds deliver a bigger, badder listening experience. Their small 9mm driver delivers clear detail and balanced tonal range, while the flexible ear cushions fit in a variety of different ears. They sit securely in your ear while blocking external noise