These Coralife Compact Fluorescent Lunar Aqualight Replacement Mounting Legs only work with certain Compact Fluorescent Lunar Aqualights. You can use the Coralife Aqualight Clear Mounting Legs for the original Lunar Aqualight fixture (which has four legs). These legs will also NOT work with the T5 Lunar Aqualight. There is even a newer style Compact Fluorescent Lunar Aqualight that has a leg set that is not compatible with this leg set. The newest style Compact Fluorescent Lunar Aqualight has directional LEDs and the leg set is symmetrical. Basically, if your leg set looks just like the leg set pictured then this leg set will work. If the legs you are replacing look different, then this leg set will not work.