The operational principle of the electrostatic condenser type is based on a system whereby plus and minus output signals are input by push-pull into two electrodes sandwiching a diaphragm with a high level of accuracy and equidistantly, resulting in the vibration of an ultra-thin membrane through the repulsive force and suction force of static electricity, which is then converted into sound. The balance method, which is considered to be the ideal for amplification, is thus extended to speakers. The electrostatic system entails input by balance, output by balance, and sound conversion by balance, and, in realizing all these features, constitutes the perfect balance system. It is the only system that makes it possible to listen to sound in the ideal manner permitted by the balance system. The new SRM-007tII is our flagship model of a driver unit intended exclusively for earspeakers characterized by their wide range, high dynamic range and outstanding operating features with full allowance made for SACD and other new-generation high-density formats. The ultra-light polymer film, only a few microns thick, realizes unprecedented response and a high degree of resolution. Since it is driven on all sides, there is almost no partitioned vibration and there is no phase distortion. Nor is there any imbalance in the sound quality of the unit or distortion caused by the network. Electromagnetic distortion also does not occur. It opens up on the world of high sound quality that is the mark of headphone listening, a world characterized by the absence of need for large output, the high degree of freedom permitted by the use of high sound quality elements for use with small signals, and the even balance between left and right unaffected by acoustic conditions in the listening room.