40 Rayovac Extra Advanced Hearing Aid Batteries, Size 675 (40 batteries Standard dial pack, 10 cards of 4 cells each). Rayovac Hearing Aid Batteries, are the best selling brand and they claim to have the world's longest lasting hearing aid batteries. Experience the world's longest lasting mercury-free hearing aid batteries - Rayovac Mercury Free, The Green Choice. Delivering 30% more battery life than other mercury-free hearing aid batteries, Rayovac Mercury Free offers consistent power and performance with an environmental focus.
