[aumoore]

interesting facts from Ron's website suggestion.

"We are often asked what the difference is between a Snell SA2000, M2000 or a K1998 certification for a helmet. All Snell tests for these specifications include multiple impact tests at -20 degrees, 78 degrees (dry and wet) and 120 degrees. The Snell M2000 specification is the base for the specs. Snell K1998, a spec designed for karting, uses a thicker shield. The SA2000, used primarily for auto racing, adds not only the thicker shield, but also the use of flame retardant paint, trim, retention strap and interior. The Snell SA2000 also meets an additional rollbar impact test."