- 8-pack of size 312 zinc air hearing aid batteries with EZ Turn & Lock design - Our longest-lasting hearing aid battery ever provides long-lasting performance to your device - Made with PowerSeal Technology to protect your devices from leakage* - Extra-long coloured tabs for easy installation - Holds power for up to 4 years in storage - EZ Turn & Lock packaging makes handling and storing the batteries easy - Delivers consistent sound quality *From leakage of fully-used batteries up to 1 week at room temperature.