This rechargeable Li-ion 18650 battery has a button top.

This makes it suitable for the various night vision and thermal optics, such as Hikmicro, that use button top batteries.
Of course it is also suitable for other compatible electronics such as flashlights, IR illuminators, spotters and more.

Please note if you have a PARD optic:
PARD often uses flat top batteries. These are shorter and these button tops often do not fit.
For these we have batteries with a flat top: AE 18650 Flat Top.