FIA standard 8858-2010 only approves helmets with the nut washer built in the helmet. If you purchase post anchors with nut washers, you accept that these anchors do not comply with the FIA regulation. If you purchase post anchors without nut washers for use with helmets having a built in M6 terminal, these are fully FIA approved. Both types of anchors (with or without nut washers) are fully SFI approved. Used with Simpson post clips.