This is an ear-back RIC digital hearing aid. Based on the digital signal processing system, 10-channel wide dynamic range compression and digital signal processing, 4 programs can match four different types of hearing loss. Through the hearing aid App, you can choose your favorite sound quality, and adjust the volume and frequency band. It can provide you with more delicate sound texture for a clearer, fuller and richer sound experience. Volume and program with auto save/memory function Low battery reminder Preprogram the boot tone prompt Startup delay APP adjustment Volume adjustment mode: Button Multifunctional button: short press to adjust the volume; long press for 3 seconds to switch the matching program 10-channel WDRC 10-channel low level expansion 10-channel maximum output limiter 32 band equalizer Intelligent ambient noise suppression (18dB) Wind noise suppression (5 levels) Acoustic comfort optimizer (5 levels) Pre-configured voice prompt Specification: Hearing aid button battery model: 312A Battery capacity: 140mAh Voltage: 1.45V Diameter: 7.9mm Package included: 1 x Hearing Aid 6 x Earplug 2 x Button Battery 1 x Storage Case 1 x English User Manual Other things not included