Material : Stainless Steel with 18k gold plating, non-tarnish, and hypoallergenic Size : 6.5 cm diameter Scan the QR code engraved on the heart pendant and your personalized letter will appear! Please send your letter via Shopee message (Max of 200 letters). To scan, simply point the QR code towards your phone camera and zoom-in on the QR code. Make sure that camera is focused on the QR code without any glares / reflection to scan properly. Try tilting the pendant and make sure that the camera is focus locked on QR code. Once focused, click the link that pops up to see your message! Each phone has different QR scanning capabilities, some phone may not have a built-in QR function and will be needing 3rd party QR code readers.  Note that an internet connection is needed to load your personalized letter. If upon scanning there is an error, just message us directly and we can correct this remotely. Product is strictly non-refundable in any case that your device is not able to scan the engraved QR. Thank you!