This is the hearing aid with a patented sound amplifier that accommodates your unique hearing profile. Unlike lesser units that simply increase the volume, this device enables one to adjust the amplification and clarification by letting you separately adjust high and low frequencies (eight adjustment levels each) for clearer hearing. Includes three silicone caps to accommodate different size ear canals. Charges via USB-to-AC adapter; a two-hour charge provides up to two weeks of power. Includes one hearing aid that can be used to fit either ear.