The Energizer Size 312 Hearing Aid Batteries are a 12 pack of zinc-air batteries with an expiration date of 09/2028. With a voltage of 1.45V, these batteries are designed specifically for hearing aids. The size 312 designation indicates the size of the battery, making them compatible with a variety of hearing aid models. The zinc-air chemical composition ensures a long-lasting power source for your hearing aid, providing reliable assistance for daily living needs.