This was created to use an Arduino Nano BLE Sense with a 9V block and phyphox.
For more information on the software I use, this is the project you are looking for:
https://hebergement.universite-paris-saclay.fr/supraconductivite/projet/arduino_nano/?lang=en
The 9V block, the switch and the cap all should snap snuggly together.
The switch is a SS-12F15 slide switch, the clip is a generic T-clip with faux leather, so nothing thick.
The red cable from the battery clip connects to the switch and from there to the Vin pin on the Arduino. The black wire connects directly to any GND pin.
The author hasn't provided the model origin yet.