Motorcycles
Depending on the type of motorcycle, the motorcycle may or may not have rear-view mirrors. Street-legal motorcycles are generally required to have rear-view mirrors. Motorcycles for off-road use only normally do not have rear-view mirrors. Rear-view mirrors come in various shapes and designs, and have various methods of mounting the mirrors to the motorcycle, most commonly to the handlebars. Rear-view mirrors can also be attached to the rider's motorcycle helmet.
Read more about this topic: Rear-view Mirror