Rayovac Extra Advanced Size 312(60 batteries)

Zinc-air battery that uses outside air as a power source. A self-adhesive tape ensures its freshness (up to 4 years) until you are ready to use it. To activate the battery, simply remove the adhesive tape. After removing the tape, wait about a minute before inserting the battery into your headset. This allows sufficient time for the air to enter and activate the battery components. Reinstalling the safety strap after removing it will not extend the battery life.