Pennsylvania Statutes Title 75 Pa.C.S.A. Vehicles § 4534. Rearview mirrors

No person shall operate a motor vehicle or combination on a highway unless the vehicle or combination is equipped with at least one mirror, or similar device, which provides the driver an unobstructed view of the highway to the rear of the vehicle or combination. This section shall not apply to any special mobile equipment, commercial implement of husbandry or implement of husbandry that is not so equipped by the original manufacturer.