Automotive Helmets

I'm racing with NHRA. Do I need a helmet, and if so, what kind?
A snell rated helmet is required for the driver of any car or truck running 13.99 seconds or quicker in the quarter mile, and for the rider of any motorcycle. Drivers can use a helmet meeting the current snell rated specifications. Professional category and some alcohol burning vehicles require a snell SA rated helmet. It is important to note that the snell rating must be designated on a tag INSIDE the helmet, or sewn to one of the helmet straps. The designation stenciled on the exterior of the helmet is insufficient for NHRA technical inspection. The inspectors will be looking for the snell rated sticker inside the helmet. Also, some tracks require a snell rated helmet on ALL drivers, so check in advance.