From the NHRA rulebook
"For all 9.99 and quicker closed-bodied cars, a full-face Snell M2000,
M2005, M2010, K2005, SA2000, SA2005, SFI 31.2A, or 41.2A
helmet mandatory; shield permitted (goggles prohibited)."
2010_Electronic_RB_v2.pdf page 68.
Clay
"For all 9.99 and quicker closed-bodied cars, a full-face Snell M2000,
M2005, M2010, K2005, SA2000, SA2005, SFI 31.2A, or 41.2A
helmet mandatory; shield permitted (goggles prohibited)."
2010_Electronic_RB_v2.pdf page 68.
Clay