The Vise Oval with "Nubs" Inserts feature tiny bumps on the inside to assist with ball grip and lift. This grip is dual sized with a different size on each end. Available in Grape only.
numbers on my insert is 31/32 31/2 - 4 i dont see this size1/24/2020 - By dan
If your insert has a large number 4 on the side then this would equal an 11/16. The 31/32 may be the outer diameter of the insert and the inner diameter would be 11/16 if the size is a 4.1/29/2020 - By Bowling.Com Staff