Push-Pull Tractor Parking Valve, Controls TRACTOR ONLY parking. Bulkhead mount, requires 7/8 mounting hole. Made of durable (EGC) Engineering Grade Composite. A better replacement for the PP-8. Will not stay in half-on/half-off position. Tractor Parking. Knobs Included: KN20902 Product Features:Made of durable (EGC) Engineering Grade CompositeA better replacement for the PP-8. Will not stay in half-on/half-off positionControls TRACTOR ONLY parking