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 Masonry, For Use In Cutting & Chopping Applications On All 7" & 8" Circular Saws.