ORIGIN 4.3-inch Rearview Mirror Monitor, 12V/24V, Dual Video Input, Backup Camera Compatible, ORG-403C

No special installation is required; simply clip it onto your factory mirror. (Compatible with mirrors between 50 and 70mm.) It's slightly larger than the factory mirror, providing a wider field of view. It's ultra-lightweight, weighing just 284g, so it won't sag.