Model Number: YKL-801-B4 Brand Name: YAKLEE Key Specifications/Special Features: This is a bone conduction hearing aid, the elderly or eardrum damaged people wear this product, can clearly hear outside the sound. This product is comfortable to wear and easy to use. SpecificationsFrequency range: 20Hz-20kHzMicrophone sensitivity: -54±2dBOperating time: 10±0.3 hoursStandby time: over 60 daysInput: DC5.0 ±0.5V, max 500mABattery: Li-ion battery capacity 3.7V 350mAh