Inner circumference: Approximately 15.5cm, with some margin of error. This item is being sold as is, so size adjustments are not possible. Larimar: 10mm Lavender Amethyst: 10mm Madagascar Rose Quartz: 10mm Prehnite: 10mm Aquamarine: 10mm Carnelian: 10mm 64-faceted Crystal: 8mm Crystal: 5mm Citrine (heat-treated): 6mm Rondel Double-strand Opelet rubber * Larimar has small flat areas, but they do not appear in the images. Please refrain from purchasing if you are concerned. * The rubber knot is not secured with adhesive. If it comes out, gently pull it back in from the opposite side of the stone. Stones may have small scratches, inclusions, color variations, dents, and natural cracks. This is a handmade item by an amateur, so please refrain from purchasing if you are looking for perfection. 7