Simplify the following text for a Grade 12 native English-speaking person.
Original: Cooper Tire & Rubber Company is a United States based company that specializes in the design , manufacture , marketing and sales of replacementautomobiles and truck tires , and subsidiaries that specialize in medium truck , motorcycle and racing tires .
Simplified: They design , manufacture , marketing and sales replacement automobile and truck tires . With their subsidiaries they produce medium truck , motorcycle and racing tires .