mounted about the compression spring holders 86 with the bottom ends 88 of the compression springs 18 abutting the top 90 of the base 78 of the seal block 12 and top 152 of the compression springs 18 abutting the set screws 148 in the longitudinally disposed side channels 142 of the astragal 30 the compression springs 18 are held in the longitudinally disposed side channels 142 of the astragal 30 under compression the extension stops 132 of the astragal 30 preventing the compression springs 18 from forcing the substantially u201c t u201d shaped member 84 out of the recesses 130 the barrel 92 of the seal block 12 is matingly slidable about the bolt 56 of the astragal 30 and the bolt 56 is matingly slidable therethrough the substantially centrally disposed hole 14 of the barrel 92 of the seal block 12 the angled edges 105 of the substantially u201c t u201d shaped member 84 matingly abut the angled longitudinal edges 150 of the astragal 30 the angled edges 105 of the substantially u201c t u201d shaped member 84 and the barrel 92 of the guide block 82 guide the seal block 12 collinearly with the angled longitudinal edges 150 of the astragal 30 and the substantially centrally disposed longitudinal channel 54 the bolt 56 being substantially aligned with the substantially centrally disposed longitudinal channel 54 the extension stops 132 and the retraction stops 134 limit the extent of travel of the substantially u201c t u201d shaped member 84 and thus limit the extent of travel of.