Features: – Digital Voice & Sound Hearing Amplifier – Universal Fit Ear-Stud – Mini Compact Hearing Amplifier Style – Battery Operated Design – Active Noise Reduction – Interchangeable Ear Tip to Seal-Out the Noise – Can be Used for Left or Right Ear – Over Discharge/Charge Feature What’s in the Box: – Hearing Amplifier – (3) Ear Bud Tips – (2) Batteries Technical Specs: – Input Noise: =28dB – Sensitivity: =35dB – THD: 4% – Max Sound Output: 110/±5dB – Frequency Range: 300-6000Hz – Working Current: =4mA – Construction Material: Engineered ABS – Battery Type: A10 (Size 10) Button Cell (1.2V, 180mAh, 0.150Wh) – Dimensions (L x W x H): 0.98’’ x 0.51’’ x 0.59’’ -inches