Ultra convenient and easy to carry. In the design of mini size， with low noise. Offers comfortable silicon earplugs in 3 sizes to fit most ears. It is beneficial for people have hearing problems. Max saturated sound pressure level:129dB ?�� 4dB Full-on acoustic gain: 50dB ?�� 5dB Equivalent noise: ?�� 30 dB Harmonic distortion: ?��5% Frequency response: 450 ~ 3500 Hz Battery: AG13 button battery Voltage: 1.5V DC Rated current: ?�� 4 mA Disclaimer: "The sale of this item may be subject to regulation by the U.S. Food and Drug Administration and state and local regulatory agencies. If so， do not bid on this item unless you are an unauthorized purchaser. If the item is subject to FDA regulation， I will verify your status as an authorized purchaser of this item before shipping of the item." Package:1 x Hearing aid 3 x Silicon ear cushions 4 x Button batteries In original package