This RYOBI Reciprocating Saw Blade 4-Piece Set is ideal for cutting into wood, metal, tree branches and roots. It includes a variety of lengths to make quick, rough cuts in timber, branches and metal. All reciprocating saw blades also feature a universal shank that fits into any existing reciprocating saw. The different lengths and TPI (teeth per inch) to cover a range of tasks and materials: 6” 6 TPI Wood Blade 6” 14 TPI Metal Blade 9” 5/6 TPI Pruning/Wood Blade 9” 14 TPI Metal Blade