RETRAC convex mirrors add safety and functionality to heavy-duty trucks, semis, buses, utility vehicles and more. They offer versatility in their application and tested quality. This USA-made, round convex mirror head features 8" diameter convex glass to provide a wide-angle view of the vehicle's blind spots and the passing lane. It is constructed from rust-resistant stainless steel and features a polished finish to provide a bright, professional accent on any heavy-duty truck. This convex spot mirror is also thoroughly tested to ensure long-lasting durability, undergoing both a vibration test and a 360-hour salt-spray test. It installs using a 5/16" offset ball stud, extending the field of vision, and the plastic ball mechanism allows for smooth, simple adjustment without ever being restricted by rust or corrosion (J-bracket and mounting assembly not included).