298818N Yellow Semi Truck Brake and 298817N Red Tractor Knobs

298818N Yellow Semi Truck Parking Brake Knobs and 298817N Red Tractor Trailer Air Brake Knob Set. TRAILER BRAKE KNOB SET: Typical Yellow Button Pc. NO.298818N, Typical Red Button Pc. MATERIAL: Stainless Steel Push and Pull Valve Knobs.