4 piece, spade bit set, wood boring, 4" length for drilling in tight spaces, double cutting spurs scribe the outside of the hole, reducing breakout, thicker cutting edge for longer drilling life, patented blue groove point & cutting edge for faster chip removal, larger shank for durability, quick change shank fits all standard 1/4" quick change chucks, set includes one each: 5/8" speedbor, 3/4" speedbor, 1" speedbor, 1- 1/2" speedbor._x000d_ _x000d_ Blue-Groove _x000d_ Fast _x000d_ 1/4" quick change _x000d_ .