Billet Aluminum Shift Knob - Worm Trails - 6061-T6 was used to manufacture this shift knob and then the knob is polished to a high luster. Unique "worm trail" design, any threaded mounting can be tapped into this knob at no additional cost, or order universal ABS mounting sleeves. Optional CNC ball nose end milled shift pattern can be ordered at bottom of the shift knob page. If a thread is custom tapped or shift patteren custom milled in knob, knob cannot be returned for refund.