Vacu Insert Sleeves allow you to get finger inserts about 2 sizes smaller than normal. The hole is drilled to 1 1/32",but the inserts need to be 31/32". This will give you some flex room between the insert sleeve and the finger holes allowing for a more comfortable grip. The best part of using Vacu Inserts is you dont need to worry about your fingers swelling during bowling and you grips getting to tight.