Series 20, 6-1/2" 36T, Construction Aluminum Cutting Ultra Thin Kerf Blade, For Fast Cutting, Anti Stick Rim Reduces Friction & Gum Up, Professional Quality Cordless Ultra Thin Kerf Saw Blades Specifically Engineered To Optimize Cutting Performance & Maximize The Number Of Cuts Per Charge Of All DeWalt 5-3/8" & 6-1/2" Cordless Saws.