on adaptor 18 and located by a surface 81 of the lobes 46 in preparation for a twisting or rotating movement of the reflector relative to the adaptor to insert the respective projections 78 into the respective grooves 64 formed between the respective sets of lobes referring now to fig4 and 7 there is illustrated in fig6 and 7 the respective positions of a reflector 20 when it is placed in a position to be connected to the adaptor 18 fig6 and the engaged and locked position fig7 respectively as illustrated in fig6 and 7 the reflector 20 is preferably provided with suitable indicia 88 and 90 indicating the direction of rotation of the reflector relative to the adaptor 18 to mount the reflector on or take the reflector off of the adaptor moreover the lobes 58 and 60 of the respective pairs of lobes are also provided with suitable indicia 92 and 94 cast or applied on the surface of the lobes and indicating the words 34 on 34 and 34 off 34 respectively including associated directional arrows indicating which direction to rotate the reflector by aligning at least approximately the indicia 90 on the reflector 20 with the correspondingly worded indicia 92 on the adaptor 18 as indicated in fig6 and by moving the reflector 20 upward or axially toward the surfaces 81 of the respective lobes 46 fig4 until engaged therewith the reflector is then in a position to be rotated in the direction of the arrow 100 in a clockwise manner viewing fig6 and 7 to move the respective projections 78 fully into the slots 64 referring.