Material: The blank rings base is made of 304 stainless steel,The surface is smooth and comfortable to wear. It has a unique luster, is durable, and is resistant to discoloration. Sizes: The blank rings base is about inner diameter 18.5mm, tray 12mm, 30pcs. Please check the size before purchasing.Easy for you to link these beads with other findings. Unique design: the ring adopts the design of stainless steel, which is very suitable for sticking beads or other items to create a unique ring. DIY accessories suitable for family jewelry making and hobbies. Easy to Use: Paste the lovely pattern with the clear glass cabochon, then cover the glass cabochons on the ring pendant tray, and then the unique finger ring is finished. Meaningful Handmade Gifts: You can turn these metal blank ring trays into delicate and fashionable ornaments with your own hands and wrap them up as a wonderful gift for your friends, family, girlfriends, birthdays, Christmas, New Year's Day, and other meaningful days.