Vise O/PO Bowling Ball Finger Inserts (Oval/Power Oval)Vise Inserts feature 3 different combinations to fit anyone’s game. The oval side provides the perfect natural feel for a smooth consistent release. The Power Oval side has a subtle 1/8″ forward pitch in a relaxed oval shape for added rotation.Vise P/S Inserts are available in 32 sizes and 11 colors.- Sizes 9/16 through 13/16 have O.D. of 31/32″ – Sizes 53/64 through 29/32 have O.D. of 1-1/32″One side of the insert is an Oval cut and the other side is a blended Power OvalDrill Size 31/32″: 9/16, 37/64, 19/32, 39/64, 5/8, 41/64, 21/32, 43/64, 11/16, 45/64, 23/32, 47/64, 3/4, 49/64,25/32, 51/64 and 13/16.Drill Size 1-1/32″: 53/64, 27/32, 55/64, 7/8, 57/64 and 29/32.