If checked, then found that rotating Bolt into the Jack Nut., parts to be assembled with Louver Duct parts by Vertical angle of Louver piece must dovetail with the pieces fit.
If verified that rotate with Jack Nut Bolt had to put the pieces Louver attributed to a piece by Duct Vertical four corners of the Louver to splice the pieces fit.
If checked and found that rotate Bolt along with Jack Nut. To bring Louver parts assembled into parts Duct Vertical by 4 corners of parts. Louver to mesh with the parts fit.