/ Size (cm) / girls 13-17 / 16-20 boys / Material Glass & Crystal & Beads / Operate and maintain / Thank you have LYLA Silver & amp; Accessories of hand-made jewelry. On this provide you with product maintenance skills, make your jewelry more long-term use. First, when you wear jewelry, do not in direct contact with water. Second, avoid direct contact with perfume and lotion (wear before use). Third, avoid wearing when engaged in sports activities (in addition to a marked style movable outside). Fourth, do not wear jewelry hot springs. Fifth, avoid prolonged direct sunlight. Sixth, when not worn, use a soft dry cloth, placed in zipper bag to save. Folder chain bag can stop air from entering, slowing oxidation, helping save jewelry. / Hand around the measurement / Hand around the size can be customized, so do not worry too big or too small. Hand around to do the calculation centimeters, with a rope around the hand circle, do the next mark, then ruler to measure. We need your hand "real Wai", so do not amount too loose or too tight.