To my knowledge, none of these products are individually "certified" by FIA. Any future standards (there are none currently in place) will consider this element as part of the entire seat assembly. Butler makes a good product also.

Another approach is to use nets

In exchange for lateral head protection, these elements hinder egress and limit visibility. If you are not presently using a head and neck restraint, you may wish to consider one that provides maximum lateral protection as an alternative. (I wont' name names.)