Montana Sapphire Castor Ring No. 3This ring is a size 7. 25. Due to the nature of this ring, it can only be sized up or down within one size. This Montana Sapphire Castor Ring features a unique setting with geometric cut Montana sapphires held securely in a stylish invisible bezel setting. It guarantees unique and timeless elegance with a bold statement. This ring can be grooved with a special date of your choosing mixed into a pattern of grooves around the band. For example, May 8th