For your consideration I have a used 15lb Storm Dark Code bowling ball. Ball has approximately 30 games on it. TBall has approximately 30 games on it. There are some sand marks around the thumb insert and other marks on the ball consistent with normal use. Switch grip installed in thumb.

Grip measurements WITHOUT thumb insert installed:

Ring finger - 4-5/16"
Middle finger - 4-3/8"

Gross weight - 14lb 14.9oz
Pin - 4.25"

Thank you!