The structural engineers of David’s Formula have developed small and delicate in-ear headphones through sophisticated arrangement of structures, meeting consumers’ needs for portable convenience. The inner structure of our earphones are minimized without compromising sound performance in terms of range and depth, while the 10O diameter embodies incomparable power, giving a deep bass sound and clear high notes. Combined with latex ear plugs, these earphones keep out the loud roars of urban living, allowing your ears to take in a free flow of musical notes. David’s Formula in-ear earphones strike a perfect balance between fashionable design and sophisticated sound performance.