Open Sesame! Sesame Ring by a US based gadget maker, Ring Theory is a passive, RFID-based contactless payment and access device, which opens the gates to the Massachusetts Bay Transportation Authority’s (MBTA) buses and subway. This charlie card built into the smart ring form-factor is a prepaid device that requires credit, or the monthly pass loaded on it in advance.
Sesame Ring is claimed to be the first wearable metro pass in the US.
It is 3D-printed. The product only ships within US.