HEARPRO SIZE 10 LONG LASTING HEARING AID BATTERY: The New Standard Of Hearing Aid Batteries PREMIUM QUALITY - Long-Lasting Zinc Air Batteries Built for Today’s Most Demanding Hearing aids. UNIVERSAL FIT - HEARPRO 10 Batteries are made to fit all hearing aids that operate using a size 10 battery. We use strict tolerance in the manufacturing process to ensure the proper fit of our batteries with your hearing aids. ZINC AIR - 1.45V Zinc Air Technology Provides Constant Operation for Life of the Battery MERCURY-FREE - Formula Proudly Produced in the USA with US & Global Parts CUSTOMER FOCUSED - HEARPRO is dedicated to give you the best customer experience possible. Email us if you have any questions or concerns.