3-pack. Diablo?s Starlock bi-metal oscillating blades feature application specific designs that deliver maximum durability and longer life in nail-embedded wood applications. These high-performance blades feature an ultra-hardened cutting edge to deliver up to 5X longer life than standard blades. Curve contact edge creates a pilot for precise, clean plunge cuts with less vibration. Black I.C.E. (Industrial Cooling Element) keeps the teeth cool and build up free for fast, clean cuts. Tool free quick-change interface fits Fein and other Starlock tools; also compatible with most non-Starlock multi-tools.