Blue Demon Company Inc. has offered American-made drilling tools since 1948. Offering a completely field-replaceable PDC drilling system. Available in four-wing from 3⅞- to 6¾-inches diameter in ⅛-inch increments. Three-wing systems available from 6¾- to 24-inches in diameter. For more information, contact 800-282-6760 or sales@bluedemon.com. www.bluedemon.com