Simple and straight design.
Basic skull ring. Looks like sharp "T".
Thickness of the ring band is about 1.5 mm in the thinnest part, but it changes a little depending on the ring size.
You can choose the size of the ring.
Please refer to size chart below. Ring Size ( Japan / US ) : Inside diameter ( mm )
If you want to know other size of rings , please refer to Wikipedia.
You can also buy other than this product. Please check out "Valley".