As explained on our Ring Guard Sizes page, the size of ring guard you need depends on the ring band (not ring size).
As in this image, the ring band is approximately 3mm in width. This ring would require the small size ring guard.
The “arm” of the guard must wrap your ring, ideally ending on the inside of the band.
You may visit our Size Chart to find out more about the other sizes of ring guards available.
The larger the ring guard size, the longer the arms are to wrap your band.