Roll cage
A roll cage is a specially engineered and constructed frame built in the passenger compartment of a vehicle to protect its occupants from being injured or killed in an accident, particularly in the event of a rollover.
Designs
There are many different roll cage designs depending on the application. Hence, various racing organizations have differing specifications and regulations, although most of these organizations harmonize their rules with those of the FIA.Roll cages help to stiffen the chassis, which is desirable in racing applications. Racing cages are typically either bolt-in or welded-in, with the former being more straightforward and cheaper to fit while the latter is stronger and more substantial.
A is a single bar behind the driver that provides moderate rollover protection. Due to the lack of a protective top, some modern convertibles utilize a strong windscreen frame acting as a roll bar. Also, a roll hoop may be placed behind both headrests, which is essentially a roll bar spanning the width of a passenger's shoulders.