Amazon.com: CR1616 Battery 3V Lithium Battery CR 1616 3 Volt Li-MnO₂ Battery 5 Pack : Health & Household
Amazon.com: Duracell 1616 3V Lithium Battery, 1 Count Pack, Lithium Coin Battery for Medical and Fitness Devices, Watches, and more, CR Lithium 3 Volt Cell : Health & Household