If they don't have a frequent-flier ID card, travelers check in online or at kiosks and get a bar code on a printed boarding pass or on a mobile phone, just like at other airlines.

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Those without printers can grab a free PayNearMe card at one of 7-Eleven's 6, 000 locations and use the card's bar code in lieu of a printed sheet.

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There's also a QR code plus its corresponding label ID printed below the foil, and scanning the former or entering the latter on qr-sennheiser.com returns a virtual copy of the foil label plus a visual description.

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Printed inside the wrappers of the bars will be a code that can be sent back to a given phone number in an SMS message to see if it wins a prize.

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