3.0 V lithium manganese dioxide. Never drop one in a 1.55 V watch.
CR1025 · 10 × 2.5 mm
CR1216 · 12.5 × 1.6 mm
CR1220 · 12.5 × 2 mm
CR1225 · 12.5 × 2.5 mm
CR1616 · 16 × 1.6 mm
CR1620 · 16 × 2 mm
CR1632 · 16 × 3.2 mm
CR2016 · 20 × 1.6 mm
CR2025 · 20 × 2.5 mm
CR2032 · 20 × 3.2 mm
CR2320 · 23 × 2 mm
CR2325 · 23 × 2.5 mm
CR2430 · 24.5 × 3 mm
CR2450 · 24.5 × 5 mm
CR2477 · 24.5 × 7.7 mm