Feature: Material: Cast Steel Color:Black Type: 12″Auger Bit Replacement Size(H x D): 31 1/2″ x 12″ Weight: 11.7 lbs Inside diameter：3/4″ Description： 31″ Long for each diameter，compatible with any Auger machine head with 3/4″ Shaft Durable cast steel pilot bit with tungsten carbide cutting tip Drills holes in all types of soil; the dirt removed is left around edge of hole in loose, easy-to-pack condition Exponentially increases planting speed and ease .