MATERIAL QR CODE. Say goodbye to the hassle of finding the optimal processing parameters. It only takes two steps: place the QR code sticker/card into the machine, then click the "Refresh background" button and immediately apply the optimal processing parameters. You can click here to learn how to use automatic QR code recognition with the P series or F series. (*Please note that the automatic scanning function requires a camera. Non-camera machines (F1/S/M1U/D) can manually scan the QR code to quickly obtain the optimal processing parameters.) Ring engraving face: 0.5" x 0.5", Wall thickness: 0.06", Diameter: 0.7", easy to use and process. Open adjustable signet ring can be engraved by all xTool machines. This ring is a multi-pack of materials that comes in three colors and can be adjusted to fit the finger dimensions. It is ideal for personalizing art decor and gifts for any occasion.