Use with HANS devices which set up for post clip anchors, containing the metal clasps at the end of the tether instead of the sewn loops for quick clip attachments. For use with SAH helmets containing a built-in M6 nut washer. FIA standard 8858-2010 only approves helmets with the nut washer built into the helmet. Fully SFI approved as well. The professional HANS post clips have aluminum bases and are sold as a pair for one helmet. Blue color.