These Renata CR2450N lithium batteries are quite unusual in shape.
The CR2450N battery has a lip around that allows it to drop into certain equipment.
If the battery you are taking out of your appliance is a CR2450N then make sure you buy this version and not a conventional CR2450.
They are used in sensors, CMOS memory back and dive computers.
These 3V CR2450N lithium batteries are Swiss Made by Renata.
This pack contains two Renata CR2450N batteries.