Silver Tone Medium Pi Rope Charm Bead Dangle. Silver Tone Medium Pi is approx. 0.59 x 0.47 x 0.08 (HxWxD) including loop. The irrational number Pi is a mathematical constant, the ratio of a circle's circumference to its diameter, approximately 3.14. It has been represented by the Greek letter since the mid-18th century. Triple plated large hole bead is approx. 13.2x2.6x10mm (HxWxD) with a hole size of 5.4mm. Our Charm Beads are compatible with most Charm Bead Bracelets. Also makes a great necklace pendant. These beads are wonderful for a starting a european large hole bead bracelet. Also available as a necklace, and bracelet. PLEASE NOTE: Our products are lead safe, but are not intended for children 14 years and younger.