Precision forming process creates sharper teeth for fast cutting. Double relief angle reduces tooth stress for long life. Matrix II bi-metal teeth for greater durability. NAIL GUARD combines an aggressive 5 tpi pattern for faster cutting, with a unique design that protects against tooth fractures. The FANG TIP design bites into wood on first contact for faster plunging. All-purpose set includes (2) 6" 4 tpi Thin Kerf Ice Hardened Sawzall blades, (2) 6" 18 tpi Thin Kerf Ice Hardened Sawzall blades, (2) 6" 5 tpi Sawzall blades, (2) 9" 5 tpi Sawzall blades, and roll-up pouch for convenient blade storage. No. 49-22-0240: Pieces In Set: 8 Pcs., Material: Bi-Metal, Application: Metal, Wood, Pkg Qty: 8, Package Type: Clamshell