Probably the coin cell batteries you're looking for: the most common CR2016 or CR2032 batteries in a handy twin-pack. If you own anything that uses these, buy spares before you run out!

Coin cell batteries are used in watches, small blinkers, and flashlights, where long service life and small size are mandatory. The list of benefits speaking for lithium batteries is long:

• Service life: lithium batteries keep your devices going for much longer
• Operations in the cold: lithium batteries keep going when alkaline stops working
• Weight: lithium batteries are lighter
• Storage: lithium batteries have a longer shelf-life
• Device protection: lithium batteries don't leak into the battery compartment even if you forget them in place

Here's a public service announcement from the responsible folks who keep their household chemicals and guns out of the wrong hands:

Swallowing these batteries may cause serious harm or death within two hours due to chemical burns or ruptured internal organs.

Made by Varta

Varta is a trusted German brand when it comes to batteries. These batteries have a long shelf-life and good output values throughout their life. It's always nice to see "Made in Germany" printed somewhere.