Includes 1/2, 3/4 and 1" bits with a 6" bit extension. Each 6" bit has a hex shank that fits all 1/4" drill chucks. Patented cutting spurs leave smoother holes in wood. The 6" bit extension will follow bits 5/8" and greater through holes. Two set screws in extension end secure bit. Comes with a hex key for adjustment. Made in the USA.