<< >> Retractable Carbide Bit Diamond core bit with retractable carbide bit that is used in ductwork applications. Specifiy thread size for retractable carbide bit when ordering. More Views Product Description Used in Offices and buildings where duct work is present Carbide bit drills through thin duct work and diamond bit drills through concrete Designed for use on "Walker Duct" material applications Additional Information Size 2-1/4"
