CR2032 Battery Pack
Replacement 3V coin cells.
$8.99
Free shipping, and 30 days to send it back for a full refund if it isn't right.
What it's good for
3V lithium, 20mm
The standard CR2032 size, so it fits the siren and most of the small electronics already in the house.
Worth replacing early
A safety alarm with a flat cell is an ornament. Swapping it yearly costs less than a coffee.
Not just for the siren
Key fobs, scales, clocks, remotes and thermometers all take the same cell.