The hottest Interchangeable Insert on the market. Get the same great feel in every ball you own with Switch Grip Interchangeable Inserts. This revolutionary two-piece insert assembly allows bowlers to remove and interchange thumb inserts from one ball to another for the same fit and feel every shot. No more fussing and fighting installing and removing tape. With just a simple "Twist & Click", bowlers can make a ball change using the same thumb or better yet change thumb size due to shrinking or swelling. ABC/WIBC Approved.

Recommended purchase

1 outer sleeve for every ball you own plus a few extras for future balls.

Depending on your thumb and how much it changes we would recommend getting 2-3 inner sleeves that you will have drilled for your normal size and then 1-2 drilled a little larger and 1-2 drilled smaller.

This will give you 2-3 regular thumbs so you do not have to switch thumb holes from your strike ball to spare ball and 1 extra incase you need to throw a different ball on each lane during your league or tournament.

The 1-2 extra drilled both bigger and smaller will give you either 1 size bigger and smaller or even better 2 sizes bigger and smaller so you will never be shut out again due to your thumb swelling or shrinking.

If you have a thumb that does changes a lot you may want to double up on the bigger and smaller sizes so that you can have at least 2 of each size so that you do not have to switch between strike ball and spare ball on each shot.

Here is the perfect 13 slug Set up if you have a problem thumb. 1 2 2 3 2 2 1

That is 3 normal sizes thumb holes, 2 that are 1 size smaller, 2 that are 2 sizes smaller and 1 that is 3 sizes smaller. Then 2 that are 1 size bigger, 2 that are 2 sizes bigger and 1 that is 1 sizes bigger.