The Peterbilt 389 Air Valve Knob is a practical and reliable product designed for easy and efficient use. Made of durable aluminum and treated with industrial hard chrome, this knob is built to last. It is available in both octagon and square shapes, allowing for a versatile fit on most makes and models. Engraved with the 389 logo, this replacement knob adds a touch of style to your vehicle. With its high-quality construction and compatibility, the Peterbilt 389 Air Valve Knob is a reliable choice for any truck owner.