that are both u201c l u201d shaped and facing towards one another the u chamber 1220 slides along these tracks the u chamber 39 s 1220 two end points have a groove shaped profile as a means to fit and slide along these tracks note fig1 also shows similar tracks 1270 under the upper box or casing cover 1170 which does not necessarily have to be there but are there to simplify the manufacturing process there is a spring 1260 that is attached via a screw to the casing cover end segment at one end and fixedly attached to the u chamber 1220 at the other end fig1 shows a bottom perspective view of the lighting system of this embodiment here the casing cover end segment 1130 is closed and the detachable casing cover segment 1150 is attached fig1 shows the same bottom perspective view but with the detachable casing cover segment 1150 detached and the casing cover end segment 1130 in the open position as shown opening the casing cover end segment 1130 causes the electrode cover 1230 to slide inward since the electrode cover 1230 is indirectly connected to the casing cover end segment 1130 through the spring 1260 the main purpose of the spring 1260 is for when the lamp 1110 is inserted and the casing cover end segment 1130 is in the closed position the spring 1260 allows for the electrode cover 1230 to stop at varying retracted positions to accommodate varying locations of the lamp 39 s 1110 electrode cap 1280 this compensates for varying lengths of the lamp electrode 1290 and electrode cap 1280 with generally greater tolerance than many commercial products this important aspect prevents the electrode.