Digital Hearing Audifonos Sound Amplifiers Wireless Ear Aids For Elderly. Features: 6-Channel WDRC 6-Channel Low Level Expansion 6-Channel Maximum Output Limiter 16 Band Equalizer Intelligent Environmental Noise Suppression (12dB) Intelligent Volume Learning Intelligent Speech Spectrum Analysis Adaptive Feedback Management System Wind Noise Suppression (3-level) Acoustic Comfort Optimizer (3-level) Autosave for Program and Volume Control Position Low Battery Warning Pre-configured Tone Indicators Power-on Delay Pre-configured Programs P1- Quiet Environment P2- Noisy Environment P3- Outdoor Volume Control Mode: Push-button 18~30dB (3dB/step) Multi-function Push Button: Short Time Push for VC 3 Seconds Push for Program Switch Specifications: Model Number: AAB100 Battery: 312 Digital Hearing Aid Hearing Aid Frenquency Range: 219~4830Hz Note Adjust Volume to the Minimum Before Wearing. Choose an Earplug of Slightly Bigger Size to Avoid Whistler. Increase Volume Gradually to Avoid Sudden Increase in Sound. If You Hear a Howling, Check the Ear (silica Gel) is Appropriate and Whether the Size of Plug is Tight, the Appropriate Choice of Earplugs and Plugged, Make Sure No Air Leakage. If It Still Does Not Work, Please Check the Chat Window Leave Me a Message. Keep the Ear Plug Clean. Remove the Battery if You Don't Use It for Long Time. . We are an international seller, your order will be shipped from abroad so please allow the necessary time of minimum 14 working days for delivery right now depending on where you ship to, due to ongoing delays in postal deliveries globally.