Duracell Hearing Aid Batteries include the very latest technology to guarantee long lasting power. Easy to handle and replace, colour-coded so it's easy to select the right hearing aid size for your device. They come in lightweight packaging that's strong and protective to keep your batteries safe. Duralock power preserve technology guarantees Duracell Hearing Aid Batteries for up to four years in ambient storage. The batteries' extra long Easy Tab makes them easy to hold, remove and replace. Mercury-free. Size 312 Hearing Aid batteries. Also known as Brown Tab, ZA312, PR41. Pack of 8.