The Spyder Stinger spade bits sets includes 1/4, 5/16, 3/8, 7/16, 1/2, 9/16, 5/8, 11/16, 3/4, 13/16, 7/8, 15/16, 1, 1-1/8 all packaged in the same pouch. Designed for wood and not for metal, it is compatible with Irwin models. The patented Stinger drill bit design features an innovative self-feeding tip. Because of the recessed edge of the threaded centre point, the bits will not jam or clog, and they automatically engage the work surface at optimal feed and speed. No additional force is needed, even if the work performed is at an angle or upside down. Spyder Stinger automatically engages the work surface for no-thrust drilling. Unlike other spade bits with a self-feeding thread point, the Spyder stinger thread point. Impact rated for use in battery powered impacting tools. The 0.25 inch speed hex will not slip in the chuck and fits quick change impact drivers. Black oxide finish provides increased durability and lubricity.