Spyder oscillating tool blades make up to 15x more cuts than standard bi-metal blades for increased service life in demanding plunge and lateral cuts in wood, nails, screws, PVC, drywall and more. A universal fit arbor ensures compatibility with all open-back oscillating tool motors. A full 2" depth of cut on each blade ensures maximum reach and superior cutting tooth velocity. Bi-metal blades feature an 8% cobalt bi-metal cutting edge that resists high cutting heat and these blades are dual/tri-plated for additional friction reduction and edge retention. High speed steel blades feature a Japanese-tooth cutting geometry that makes the cleanest cuts in soft and hard woods. These blades are not compatible with Starlock tools. 5pc set includes: (2) 1-3/4-in wood & nails, (1) 2-1/2-in wood & nails, (1) 1-3/4-in clean wood, (1) 1-1/4-in metal cutting blades