This is a 7/8" (22mm) Blu-Mol Bi-Metal Hole Saw Product Number 6531. This Hole Saw is Brand New in Blister Wrapped Packaging. Made in the USA. Features & Benefits: *Bi-Metal Construction Create Sharper, Longer Lasting Teeth. *1-7/8" (48 mm) Cutting Depth Cuts Though 2 x 4 In A Single Pass. *4/6 Positive Tooth Configuration Allow for Faster Cutting, Smoother Cuts, and Less Vibration. *M-3 High Speed Steel Cutting Edge Provides Shock Resistant Teeth and Resists Tooth Strippage. *3/16" (5 mm) Thick Heavy-Duty Backing Plate Eliminates Need For Drive Plate. *10o Positive Rake Tooth; More Aggressive Cutting. Application Information: *Create Holes For Pipe and Tubing Installations, Door Lock Installations, Electrical Conduit, Hoses, and Antennas. *Ideal for Plumbing, Construction, Aircraft, Electrical, Maintenance, and Automotive Applications. *Use in Steel, Aluminum, Brass, Cast Iron, Plastic, or Wood. This Hole Saw to be Used With a 1/2 - 20 Thread Arbor. They Are Located in the Arbors & Pilots Sections of Our Store.