Renata 389 (10 Pack) of 1.55 Volt 85mAh Silver Oxide Coin Batteries. Applications may include calculators, watches, film cameras, instruments, cash registers, or FA instruments (measuring instruments, onboard microcomputers, sensors). 1.55 Volt 85mAh Silver Oxide 389 Coin Cell Battery (Sold ten Per Carded Pack). Mercury Free. --- Brand: renata Packaging: Carded 10 Pack with Tear Strips / Description: This is a 1 cell battery for Consumer and Industrial Applications. Chemistry: Silver Oxide Measures: 0.1 (2.54mm) X 0.5 (12.70mm) Diameter