ok3609
03-08-2012, 05:37 PM
I am interested in finding an adjustable thumb insert similar to one I found in a house bowling ball. It is not an interchangeable insert. Instead, this one actually can be adjusted with a screw driver. The insert is blue and has a screw at the bottom of the hole which turns to enlarge or shrink the thumb hole. If anyone is familiar with this type of insert please post a reply.
Duane
Duane