[Easy Operation]CHOSGO V402R is controlled by a simple button. Press and hold to turn on, press and hold to turn off. Quick press to change the volume longer press to change programs. It couldn't be easier. 8 volume levels and 4 program settings quiet, noisy, conversation, outdoors. [Noise Cancellation Technology] Auto Environmental Noise Cancellation Technology and Wide Dynamic Range Compression to ensure you can hear clearly speech.Dual microphones, sound localization technology,improves sound direction perception, enhances hearing naturalness and clarity. [Advanced DSP Chip]V402R hearing aids feature a 16 Channels Advanced DSP chip, offering unparalleled sound quality and clarity. And with Automatic feedback suppression,truly achieve almost zero whistling, and always maintain high quality sound quality, allows you to wear open fit domes for better connection with the world around you.