The base inner diameter is 16. Only size down from inner diameter 13 to 16 is possible. If you want a size larger than 16, please confirm if it's possible before purchasing m(_ _)m ※ The stone meanings for amethyst are "sincerity," "nobility," "peace of mind," and "true love." Known as the birthstone for February, it's also called the "guardian stone of love" and is popular as a charm for fulfilling love. It brings peace and healing to the heart, and is believed to enhance mental stability and concentration. ※ Lepidolite, as a power stone, is called the "stone of transformation" and is said to bring relaxation, stress reduction, patience, and concentration. It features a sparkling luster and a gentle color palette of pale pink and purple. I post videos on Instagram ▶︎ ichigohime__ Please read the profile before purchasing. I do not accommodate metal allergies, but if I have the stone in stock, I may be able to remake the item without the metal parts, so please check before purchasing ( ´._.`) This is completely handmade, so please understand before purchasing. ※ Please check the images carefully and make your own judgment. If you have any questions or concerns, please ask before purchasing. Returns, refunds, and exchanges are not accepted after arrival. I am a handmade seller! Please understand. If you are looking for perfection, please purchase from a shop. (※) The price includes shipping, packaging, and handling fees. I do not understand requests for bulk discounts based on the shipping cost, so I will decline them. (※) If you would like a discount or a discount for multiple purchases, please leave a comment. m(_ _)m If there is no comment, I will decline. Please also read the profile (♡ᴗ͈ˬᴗ͈) I do not accept custom orders, only size adjustments.