Panasonic's hearing aid batteries are ideal for the latest generation of digital, wireless and multi-programmable hearing aids. Packaging benefits: Convenient dial wheel: extra long tabs for easy removal. Performance benefits: traditional 1.4V design, but measure 1.45V, offering the same performance as 1.45V cells. These batteries perform better than most mercury free designs promoted by other brands. Panasonic is the world's largest battery manufacturer and the number one hearing aid battery brand in Japan. Includes a free Battery Holder Keychain, which stores 2 spare batteries!!