3D printed?!?

Yes, Sesame Rings are 3D printed on state-of-the-art printers, then hand assembled, nourished with lots of love and care!

The material used is TSCA (Toxic Substances Control Act) compliant.

How do I use it?

The ring is so much smaller than a card. To optimize each reading, tap right in the center of the card target.

Can I try it on?

Sure. Head down to one of these physical store locations carrying Sesame Rings. If you're planning on purchasing it there, be sure to call in first to check on the availability of sizes!

1. MBTA Gift Store (WardMaps) (1735 Massachusetts Ave, Cambridge, MA 02138) 617-497-0737

2. ICA Boston (100 Northern Ave, Boston, MA 02210) 617-478-3100

3. MIT Museum Store (MIT design only) 617-253-5927

4. Felicity Sweets (579 Tremont St, Boston, MA 02118) 617-262-0707

5. Kulturez (36 John F. Kennedy St #2, Cambridge, MA 02138) 617-661-3865

6. Black Ink Cambridge (5 Brattle Street, Cambridge, MA 02138) 866-497-1221

7. The UPS store (955 Mass Ave, Cambridge, MA 02139) 617-868-5055

Is it waterproof?

Yes. Watch this!


You will need to register your ring's unique ID on the Charlie Card Web Program. We have two methods to retrieve your ring's unique ID:

Method 1 - T Station

Tap your ring at the top up station and go to Card / Ticket information

Tap your ring at the top up station and go to Card / Ticket information

Your serial number is displayed top left (image from  mbta.com )

Your serial number is displayed top left (image from mbta.com)

Method 2 - NFC-enabled mobile phone

Get the NFC TagInfo app (free, link below), scan your ring on the back of your phone, and then open Tag Information.

Now for the nifty trick. :-) Convert the unique ID (UID) shown to decimal value! You may use this website:

Done! Charlie Card for comparison:


The numbers you generate from these two methods correspond to the 5-XXXXXXXXXX on the card, but you will not actually see a 5- on the screen in either method.

Does the Sesame Ring expire like a Charlie Card?

Yes, just like the Charlie Card, your ring has a 10 year lifespan.

Can I customize the ring with my own logo?

Sounds like fun! Drop us a message and we can work out the details :)

What about keyfobs, necklaces, bracelets?

The good thing about the ring is that you can use it as a key chain too, as some of our beta users have!

We see the benefit of having other designs, and we'd love to include more form factors. We're in the midst of scoping out demand for this, and we'll post updates for any new changes.

On a side note, we had experimented with several forms such as bracelets, phone cases and key fobs. We settled on the ring because of various reasons including the fact that it was the most fun to fist bump the card target!

The Sesame Ring is possibly a start to a fresh new perspective on RFID wearable technology for common activities in our lives. And we are glad you are part of this :)