- Total of 48 Premium Zinc Air Batteries
- Compatible with all Size 312 Hearing Aid Batteries
- Up to 4 Year Shelf Life
These are the top of the line batteries from Rayovac, with up to a 4 year shelf life and guaranteed freshness. Rayovac Proline are only sold through Audiologists and Hearing Aid Dispensers.
According to Rayovac, Proline Advanced are the longest last