a car card 56 as shown in fig4 leg 188 of reflector termination 184 has a ridge or rib 190 extending upwardly which as described below engages the upper edge of the card panel 60 in combination with a bump or rounded ridge 192 extending along reflector 106a in use by removing screw 83 bezel 84 is permitted to swing about pivot 22a to the open position shown in dotted lines in fig4 it will be maintained in that position by its weight hanging from the pivot pins in this way ready access is given to the fluorescent tube and sockets for maintenance when needed the bezel 84 is formed also with longitudinal grooves 193 into which may be slid the edges of a diffuser or lens 195 which is retained in the bezel 84 both in its open and closed positions as seen in fig4 when the lower edge of card panel 60 is engaged by a screw or other removable securing means pivot pin 36 is adjacent edge 172a of pivot bore 172 at the same time the flange 176 of card panel 60 supports an upper edge of card panel 60 on rib 190 formed in reflector 106a in accordance with this embodiment of the invention access to an air plenum 118 above card panel 60 is obtained by releasing the lower edge of card panel 60 from the batten 20 as in the previous embodiments then by sliding the panel leftward so that pivot pin 36 engages edge 172b of bore 172 the flange 176 is withdrawn from between rib 190 and rounded ridge 192 permitting rotation of the card panel 60 about pivot pin 36 to an open position as shown in fig5 as card panel 60 is pivoted the flange 176 of extension 174.