fig2 fig3 and fig1 these openings 32 allow for placement of spring actuated locking mechanisms 150 fig1 fig1 fig1 fig1 and fig1 the spring actuated locking mechanisms 150 are molded plastic which include a molded or drilled hole 157 fig1 fig1 fig1 and fig1 a metal strip spring 152 fig1 and fig1 has machined holes 153 and 156 the frame 30 is then attached to the metal strip spring by means of passing a rivet 155 fig1 through holes 153 and 151 fig1 and fig1 the spring actuated locking mechanism 150 is also riveted 158 through holes 156 and 157 fig1 fig1 fig1 and fig1 thus securing the spring actuated locking mechanism 150 onto the frames 30 fig1 and fig1 reflective material may be added to the outer facing surface of the spring actuated locking mechanisms 150 fig1 the lower panel units 22 and 23 fig1 fig2 and fig4 include reinforced panel sections 33 between frames 30 the lower panel units 22 and 23 fig1 are placed within the internal cavity 88 fig1 of the upper panel units 20 and 21 fig1 and screws 91 fig1 are inserted to prevent the lower units 22 and 23 from dropping out of the upper panel units 20 and 21 fig1 the joined upper and lower panel units 20 and 22 fig1 are then attached to the joined upper and lower panel units 21 and 23 fig 1 by bolts 82 fig1 and fig7 passing through the molded extrusions 120 fig1 of the upper panel unit 20 fig1 fig1 fig1 and fig1 and the molded extrusions 81 of the upper panel unit 21 fig5 fig6 fig7 and fig8 nuts 92 fig7 are attached to the bolts 82 fig7 the frame locking assembly is comprised of two metal plates 181 and 182 fig1.