The Rayovac Size 312 Extra Advanced Hearing Batteries are high-quality, long-lasting batteries designed for behind-the-ear hearing aids. With a power source of battery, these brown-colored batteries come in a pack of 64 and have an expiration date of 2028. Specifically designed for analog sound processing, these batteries are suitable for both ears and are replaceable for continuous use. Made by the trusted brand Rayovac in the United States, these hearing aid batteries offer reliable power for daily living aids for adults with hearing assistance needs.