INVISIBLE DESIGN: 1 This hearing aids is ergonomically designed to fit perfectly in the ear canal, so you don't have to worry about dropping or losing it, and you don't have to feel embarrassed about wearing a hearing aid with its natural invisible appearance. RECHARGEABLE FUNCTION: 2 This hearing aids comes with a rechargeable function, which eliminates the hassle of constantly replacing batteries and makes it more environmentally friendly, and the portable charging case adds convenience by allowing the user to recharge the batteries automatically while on the go to minimize the hassle of power outages. EASY TO USE: Open the charging case and take out the hearing aids to turn on the hearing aids, and at the same time, adjust the volume button according to your needs, this small device can let you hear the world's clear and wonderful sound again. Note: Wearing whistling is a normal phenomenon, adjusted to disappear! DISPLAY DESIGN: This hearing aids comes with a display, you can visualize the remaining power of the charging case and keep away from charging anxiety, the charging case only needs to be charged for 2-3 hours, you can get 45 hours of spare power, which can provide 5-6 times of spare power for the device. COMPLETE ACCESSORIES: there are complete accessories in the box, along with an instruction manual to make operation easier.