Please use this for any tech official did not take the time to learn the updated NHRA rules that were posted April 14, 2016. This is the official date that NHRA corporate office in Glendora, CA approved and amended the NHRA rulebook. This amendment to section 20 of general regulations clearly states that the Whitfield 850 cert/spec cage is legal and will pass tech if welded in correctly. Feel free to print this and carry with you to the track.