https://www.adafruit.com/product/67
Adafruit Industries, Unique & fun DIY electronics and kits : -
battery holderswitchplug
https://www.seeedstudio.com/DevDuino-Sensor-Node-V1-3-ATmega-328-RC2032-battery-holder-p-1774.html
Shop DevDuino Sensor Node V1.3 (ATmega 328) - RC2032 battery holder at Seeed Studio, we offer wide selection of electronic modules for makers to DIY projects....
sensor nodebattery holderatmega
https://www.instructables.com/Another-18650-Battery-Holder/
Another 18650 Battery Holder...: Yes, this is another 18650 battery holder... but with some very useful features in my opinion!
battery holderanotherstepsinstructables