Feature: 1. 312 BATTERY: The rechargeable unit can be used with a variety of hearing amplifier devices that use 312 batteries and generally lasts 7‑10 hours for non‑Bluetooth hearing aids and 3‑6 hours for Bluetooth hearing aids. 2. CYCLIC CHARGING: Button battery charging case can be charged and cycled, equipped with a USB charging cable, you can charge it at any time. 3. TWO BATTERIES: Contains two batteries to ensure that your hearing amplifier is charged at all times and can be purchased with confidence. 4. PORTABLE DESGIN: Small and light enough to take with you anywhere, whether you are traveling for business or pleasure or on the go, you can always power your hearing amplifier. 5. LONG LASTING: Contains 2pcs 312 button batteries with 155mAh capacity, ready to power up your hearing amplifier device. Specification: Item Type: Hearing Amplifier Batteries Charger Product Material: ABS Product Use: can be applied to a variety of hearing amplifier using 312 batteries, for non-Bluetooth hearing aids, they typically last 7-10 hours; for Bluetooth hearing aids they typically last 3-6 hours Matching Batteries: 2 x 312 batteries (built in) Battery Capacity: 2 x 155mAh . Package List: 1 x Charging Box1 x USB Charger2 x Button Battery