The MILWAUKEE Reusable QUIK-LOK Arbor Hole Enlargement Adapter is intended to be used when needing to increase the size of an existing hole. This adapter works with all thread sizes and can increase existing holes from 9/16" up to 6-7/8". The Pin Adapter design prevents thread stripping and binding when using large diameter hole saws or encountering high torque. Only use the internal threads for the guide size; they are not intended to be used for cutting. This adapter is only for use with the Milwaukee QUIK-LOK Hole Saw Arbor System.