The Mack 20QE3333A Shift Knob 13 Speed Shifter Valve is a new old stock product designed for heavy equipment, specifically compatible with Volvo and Mack equipment. This valve, manufactured by Mack, is a genuine part that ensures smooth and precise gear shifting in your machinery. With its durable construction and reliable performance, the Mack 20QE3333A Shift Knob is a valuable component for maintaining the efficiency and functionality of your heavy equipment.