Product Description:The inner diameter of the necklace is 15 inches. It is a choker-style and the piece cannot be modified for length, so be sure to measure the base of your neck for fit. The outer diameter (bottom strand) measures 18 inches. The width of the piece (across the three strands) is 1.5 inches. The moonstone beads are 8mm in diameter and the garnets are approx. 4-5mm.