This mother's necklace can be personalized with the three to seven 2. 5mm birthstones you select set within the necklaces 45. 0 x 10. 0mm bypassing design. The piece is centered along your choice of a 14. 0-inch, 16. 0-inch, 18. 0-inch or 20. 0-inch cable chain that secures with a spring-ring clasp.