NFC/RFID Rings
If you found this page you’ve probably acquired one of the BSides Leeds 2025 3D printed NFC rings.
These rings contain a slot that should accommodate a flexible, waterproof, anti-metal rewritable nfc/rfid ntag213 tag of either 6x15mm or 10x20mm depending on which version you got.
The tags are re/rewritable using most nfc compatible phones – if you can use your phone to pay for shopping then you can probably use it to write/read the tag.
Tested on iPhone and Android
Is it pretty? – Nope
Does it have a long range? – nope – you’ll have to hold it right on the phone but it will work
We would encourage people not to discard the rings or nfc tags, the aim of giving these away at the conference is to nudge you to embrace the hacker ethos of learning something new or thinking about something in a different way. Think of an innovative use for the rings or tag – program it with a business card or linkedin or linktr.ee link, door access for a building, triggering an automation, injecting an xss or log4j payload, sending a text message or just to rick roll your friends.
What can you use the tags for?
You tell us!
But here are some ideas from apps;
How do you write to a tag?;
Here are some simple guides and suggested apps;
Android Guide: https://www.nfc-tag-shop.de/info/en/tutorials/android-write-nfc-tags/
Android App: https://play.google.com/store/apps/details?id=com.nxp.nfc.tagwriter
iPhone Guide: https://www.nfc-tag-shop.de/info/en/tutorials/nfc21-tools-read-and-write-nfc-tags-with-iphone/
iPhone app: https://apps.apple.com/de/app/nfc21-tools/id1496636288
Windows Guide: https://www.nfc-tag-shop.de/info/en/tutorials/nfc21-writer-write-nfc-tags-in-windows/
Windows App: https://tools.nfc21.de/
How do you read a tag?
Make sure your phone has NFC turned on and is a modern enough phone (iPhone 7 upwards should be ok)
Hold ring to front, back, top wherever it registers best for you (android usually on the back middle, iPhone front top but YMMV)
If nothing happens it may be blank ready for you to write to it, so dive on in – otherwise it should be programmed to open a webpage (if we get enough time to program several hundred rings in the few hours between them arriving from the factory, the rings coming off the printer all on the day before the conference!)
Sustainability;
We acknowledge that this may be seen as adding unnecessary plastics into the environment.
Each ring contains just less than 2g of PLA filament.
The filament used was cornstarch or sugarcane based (not from petroleum based sources). Some of the filament used was made from recycled materials. Where possible filament was supplied on recyclable cardboard reels.
The filament, being PLA (Polylactic Acid), is classed as partially recyclable. This means that it is biodegradable and compostable under industrial conditions, but standard recycling facilities do not always accept it.
(PLA can also be ground into small pieces and re-extruded into new filament using a filament recycler.)
The NFC tags are not easily recyclable.
Tech Details of the tags:
| Name | 13.56MHZ nfc ntag213 HF rfid tag sticker |
| Model and Size | Size: 6*15mm or customized size |
| Frequency | Hf 13.56 MHz |
| Read range | 1-15cm (depending on application/ reader/antenna/install sites) |
| Protocol | ISO14443A forum type 5 compliant |
| Type | passive |
| chip | NXP NTAG213, other chip can be optional: NTAG 215 ,MIFARE, I-CODE, Ultralight,… |
| Function | Read and write |
| Storage | 144bytes,1444byte,504Byte,1K BYTE…..(can be optional) |
| Material | FPC |
| The service life | 100000 rewrite Times, 10 years of data retention |
| Using the environment | Temperature: – 50~ + 85 ℃ |
| Anti-jamming | strong |
| Wide application | books library, door control access asset inventory ,school students , sports club clothing, warehouse ,vehicle car, shop store, etc. ….management |
| Installation | sticker adhesive |