7″, Masonry Abrasive Blade, 5/8″ Diamond Knock Out Arbor, Metal Arbor Prevents Shearing, Double Reinforced Fiberglass For Increased Durability, Industrial Formulation & Bonds Provide Long Life, For Fast & Economical Cuts In Metal & Masonry, For Use In Cutting & Chopping Applications On All 7″ & 8″ Circular Saws.