The Hole Saw screws into this 3/8" Arbor, which locks the saw into place without tools. The Arbor provides a ¼" pilot drill bit to center the Hole Saw on the product you're drilling into. The pilot bit can be replaced by loosening the set screw on the side of the Arbor.
WARNING: Carcinogens: This product can expose you to chemicals including Lead, which is [are] known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov.