The Reizen Mighty Loud Ear 120dB Personal Sound Amplifier for the hearing impaired is a powerful amplification device with a built-in microphone for clear and loud delivery of voice and sound through the dual earphone. Loudness is user controlled with the variable volume control dial, which also serves as the on/off switch. The red LED on top of the unit glows when turned on. This lightweight, compact, personal hearing amplifier can pick up sounds at a distance up to 100 feet away. Handy built-in belt clip allows you to attach it to your belt, shirt pocket, or clothing. Includes 2 AAA batteries and dual earphone. Additional earphones are available to use as spares or replacements. 90-Day Manufacturer's Warranty. MAIN UNIT SPECIFICATIONS Sensitivity: 120dB (plus-or-minus 3dB per MW) Frequency Range: 10Hz - 30KHz Operating Current: 14mA Estimated battery life: 48 hrs Dimensions (LxWxH): 1.75in. x 0.75 in. x 2.50 in. Weight: 1.8 oz DUAL EARPHONES SPECIFICATIONS Impedance: 8 Ohm Sensitivity (S.P.L.): 112dB plus-or-minus 3dB Caution: This product is not water-resistant. Please Note: This is not a medical device. For hearing problems, please consult a physician. Product dimensions (imperial): 2.5 inch H x 1.75 inch L x 0.75 inch W Product dimensions (metric): 63.50 mm H x 44.45 mm L x 19.05 mm W