This hearing amplifiers is a great solution for those who are suffering bad hearing condition or hearing . Professiuonal audiological theoretically designed with digital sound noise reduction processing, this ear device actively reduces background noise to provide great hearing to the maximum. With handy working mode button and volume control button, the user accurate adjustments in no time. A wonderful choice for the hard-of-hearing people, the deaf, the elderly, the hearing-impaired, etc. Features - SOUND AMPLIFIERS: Designed by expert audiologists with professional sound noise reduction process, provide clear and loud sound. Help the user the pleasure of listening to sounds or talking to others. - DESIGN: Mini size and light , the kit can easily fit into your pocket for easy storage and add no burden to your ear. - EASY TO USE: With handy on and off button and volume control that allows the user to make accurate adjustments in no time. - COMFORTABLE: silicone ear buds won’t hurt your ears, offering the most comfortable wearing. - WIDE USE. Suitable for hard-of-hearing users, the deaf, the elderly, the hearing-impaired, etc. - PREFERENTIAL present BOX. Different size noise cancelling earplugs for selection and a storage box is included. Specifications - - Material: ABS, silicone - Item Size: 10 x 9 x 4 cm - Type: Mini BTE - Output: 129 &plusmn; 4 - : 4 &plusmn; - Distortion: <=5% - Frequency Range: 450~3500 Hz - Input Noise: <=30 - Battery: A675 Zinc Air Battery (Without Battery) - Working Voltage: .5V - Working : <=3mA Note: - Adjust volume to the minimum before wearing, and increase volume gradually to avoid sudden increase in sound. - Choose an earplug of slightly bigger size to avoid . - 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. - Keep the ear plug clean. - Remove the battery if you don’t use it for long time. Package list: 1 x F-998 4 x Earplug (different sizes) 2 x A675 Zinc Air Battery ​(Without Battery) 1 x User manual 1