be discussed in more detail hereafter the keepers 150 are operative to provide a tolerance and finder system for an overhead door to ensure that when the overhead door is lowered onto the panel 123 the bottom of the overhead door is longitudinally aligned and seated upon the top 143 of the panel referring back to fig7 in this exemplary embodiment an aluminum cap 170 is seated upon the top surface 143 and similar aluminum caps not shown are seated on the lateral longitudinal sides of the panel 123 the aluminum caps 170 extend substantially the entire length on top of the panel and aluminum caps extend substantially the entire height of the panel on each side each cap 170 comprises a base surface 174 and a pair of perpendicularly extending legs 175 that collectively define an opening having a rectangular cross section this rectangular cross section approximates the rectangular cross section of the panel 123 so that the front and rear walls 126 128 of the panel 123 are compression fit within the opening of the cap 170 those skilled in the art will realize that the caps 170 may be mounted to the panels 123 using other techniques such as without limitation adhesives or mechanical fasteners in addition those skilled in the art will realize that the legs 175 of each cap 170 are tapered at 45 degree angles shown as angle u201c a u201d in order so that the horizontal and vertical caps 170 to abut one another.