Engine Works NHRA-approved engine diapers are designed to keep oil off the track during a catastrophic failure. This non-SFI engine oil containment device is made of high-quality material and fits most motor and oil pan combinations when installed properly. It includes adjustable straps that can be wrapped around frame rails or tabs that can be installed on header fasteners. Most sanctioning bodies require engine ballistic restraints for their classes of racing. Whether or not the association you race with makes it a mandatory item, it is just common sense to install one on your race car.