PowerOne P312 Hearing Aid Batteries 10 Wheels 6 per Wheel PowerOne Zinc-Air Mercury Free batteries are top of the line, industry standard setting in hearing aid batteries. PowerOne brand batteries stand out amongst more conventional brands by providing longer run times, and all around improved performance (higher audio power, greater clarity, and better frequency response). Specifications: • Battery Size: 312 • Battery Capacity (mAh): 170 • Battery Chemistry: Zinc Air • Battery Voltage: 1.45 • Battery Terminal Type: Pressure Contact • Battery Shelf Life: 3 Years • Product Certifications: Mercury-Free