Earthquake’s® Spline Shaft to Smooth Shaft earth auger bit adapter is designed to connect an Earthquake spline shaft earth auger powerhead to a 7/8” smooth shaft earth auger bit. This rugged adapter is made from alloy steel for added strength, and a rust resistant finish ensures this adapter will stand the test of time. An Earthquake Quick Connect Coupler™ is included for easy, tool-less earth auger bit change-out.