A comparison chart for what?
Solo Helmet Specifications
The SCCA Solo Events Board has acknowledged the Snell Foundation’s announced intention to delay publication of its 2015 helmet standards, by publishing a Member Advisory in the November Fastrack that states Snell 2000 helmets are considered compliant for use in Solo competition for 2015. The 2015 SCCA Solo Rulebook specifies:
All helmets meeting the latest or two immediately preceding Snell Foundation standards (SA2015, SA2010, SAH2010, SA2005, SA2000, M2015, M2010, M2005, M2000, K2010, K2005, K9, SFI standards 31.1, 41.1, 31.1A, 31.2A, 41.1A, 41.2A or British spec BS6658-85 type A/FR are acceptable for competition.
Formula Junior drivers must use helmets meeting the above, SFI 24.1 (Youth Helmets), Snell CMR2007 (Children’s Motorsports Restricted), or Snell CMS2007 (Children’s Motorsports Standard) specifications. Also, Formula Junior helmets must be of closed face design incorporating full face shields and chin bars.