The triquetra, also known as a "trinity knot," is believed to represent the three promises of a relationship such as to love, honour, and protect, and can be found as a design element on Claddaghs and other wedding or engagement rings. - http://en.wikipedia.org/wiki/Triquetra

The original Solidworks model is also available for download.

Successfully printed at 0.1mm layer height in PLA on a Flashforge Creator (and more recently on a Bambu Carbon X1 at 0.28mm layer height in PLA).  Was also successfully printed in Bronze-filled PLA on Flashforge Creator.

More Bronze Print Info: Printed with ColorFab's Bronze-Filled PLA at their suggested print settings on a Flashforge Creator. Afterwards tumbled in a rock-tumbler with ball-bearings of differing sizes for several days and sanded with 600-grit sandpaper. Has a dull shine - looks more like stone/clay than metal. Has a nice bit of weight to it.