The base inner diameter is 16mm. Size adjustments are only possible for inner diameters of 13-16mm. For sizes larger than 16mm, please confirm if it's possible before purchasing m(_ _)m White Garden 10mm Freshwater Pearl Baby Pink 8mm Crystal 8mm ※ White Garden is said to have effects such as purifying the heart, stabilizing the mind, relieving stress, and improving intuition, and is especially associated with the stone words "pure healing" and "calm mind." It is also popular as a stone to bring about good relationships, business development, and good fortune. ※ Freshwater pearls are said to symbolize healing, good luck, beauty, and the power to overcome difficulties. Wearing them is expected to bring out the wearer's beauty, support the release of emotions, and protect against evil spirits. I'm posting videos on Instagram ▶︎ ichigohime__ Please read the profile before purchasing. I do not accommodate metal allergies ( ´._.`) As these are completely handmade, 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. (※) Price includes shipping, packaging, and handling fees. (※) Discounts are not offered during time sales. If you would like a regular discount or a discount for multiple purchases, please leave a comment. m(_ _)m If there is no comment, your request will be rejected. Please also read the profile (♡ᴗ͈ˬᴗ͈) I do not accept custom orders, only size adjustments.