Billet Aluminum Shift Knob - Ball - 6061-T6 was used to manufacture this shift knob and then the knob is polished to a high luster. 1 7/8" round aluminum ball, any threaded (3/8" and over) mounting can be tapped into this knob at no additional cost. If a thread is custom tapped in knob, knob cannot be returned for refund. Please e-mail us your desired thread size after ordering, reference order number from conformation. Thread size will be 3/8-20, if no thread size is specified.