In order to be sure you are selecting the correct grill or cover for your lamp, please measure the diameter of your lamp at its widest point and compare to the measurement of the cover you are looking at.
510 Series Lamps are approx 4"
520 / 40 Series Lamps are 6.25"
525 Series Lamps are 6.25"
530 Series Lamps are 3.5"
540 Series Lamps are 5"
550 Series Lamps are 5" and only have horizontal grills
560 Series Lamps are 6" and only have horizontal grills
570 Series Lamps are 7" and only have horizontal grills
580 Series Lamps are 6.75" and only have horizontal grills