CR2032, CR2016, CR2025, CR2450, CR1220, CR1620, CR1616 Batteries. CR2450, CR1620, CR1632 CR1616, CR1220 CR2032, CR2016, CR2025 Motherboards (CMOS battery). Button batteries react with saliva to create caustic soda, which is the chemical often used to unblock drains.
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