Ansen Tools AN 303 Extra Long 12-Inch Spade Bit Set Made from drop forged and heat treated alloy steel for extra long life Use in 1/4" or larger power drills Ideal for use with hardwood, softwood, plywood, drywall and plastic The Center hole used for wire pulling The set includes 3/8", 1/2", 5/8", 7/8", 3/4" and 1"