Milwaukee 3/8" Shank Large Thread Quick Change Arbor is designed to fit all drill chucks 3/8" and larger, as well as hole saws 1-1/4" and bigger. Crafted from hardened steel, this arbor exceptional durability and reliable performance for your drilling needs. Its large thread quick change feature allows for fast and easy swapping of hole saws, making your work more efficient and convenient. Model Number: 49-56-7250