2 x Renata LR44 Swiss Made Alkaline Coin Cell Battery: Amazon.co.uk: Electronics & Photo
Energizer 364 1.55v – Battery World
Amazon.com: Duracell 384/392 Silver Oxide Button Battery, 1 Count Pack, 384/392 1.5 Volt Battery, Long-Lasting for Watches, Medical Devices, Calculators, and More : Health & Household