Most Durable Hole Saw. Period. New 3.5 TPI Tooth Design Modular Connectivity with ALL PACKOUTâ„¢ Components All-Access Slots for Easy Plug Removal Increased Pilot Visibility for Accurate Hole Placement Thermoset Coating for Faster Cutting Limited Lifetime Tooth Break Warranty IP65 Rated Weather Seal Clear Top for Easy Identification of Contents Made in USA