NFC Wifi Key

For easily configuring your wifi for your guests. The head contains an NFC-tag, which you can program using an NFC-compatible device. I used [this app](https://play.google.com/store/apps/details?id=com.wakdev.wdnfc&hl=da).
EDIT: Turns out you can do this without an app: Just hold down on the network name and then press "Write to NFC".

I used [these](https://www.amazon.de/dp/B00BTKAI7U/ref=pe_3044161_189395811_TE_dp_1) tags specifically. They measure about 23 mm in diameters.